Cleveland at half past ten P. M., and spent there some hours. It is a thriving town, and a regular stopping place for steamers, but like almost all the towns on this lake, is without a natural harbor, the only shelter to vessels being a long pier stretching into the Lake.

June 21st.-Weather fine and warm, with smooth water. Arrived at Detroit at half past eleven, and left at three P. M. Near the entrance of Lake St. Clair we were surrounded by numbers of black terns, (Sterna nigra,) which, at a moderate distance, were distinguishable from the swallows by which they were accompanied, only by their superior size. Numbers of slender gauze-winged insects, (Ephemera, Phryganea,) with long antennæ, and some with two long filaments projecting behind like the tail feathers of the Tropic bird about the boat, and on the water. In the St. Clair straits there were a few ducks, even at this season, though nothing like the vast flocks to be seen here a little later in the season.

We were sounding constantly through these straits, having on an average about three feet below the keel in the channel, our boat drawing seven feet. The shores are low, marshy and aguish, with woods at a distance, and scattered log-houses. This remarkable extent of mud-flats, (some twenty miles across,) is covered with only a foot or two of water in most parts, and even the channel is so shallow that the larger boats have to discharge a part of their cargo into lighters while passing it, and are often delayed here many hours. Even our boat continually touched, as was evident from the clouds of mud she stirred up. To make and maintain a proper channel for such a distance, is an undertaking much called for, but not to be expected of single States, nor is there any one State principally interested in it. One would hope, therefore, that the General Government may before long do something about it.

The water over these flats is still as green as that of Lake Erie, and not more turbid. About 10 P. M. we put in to wood, and remained until 7 A. M., taking in sixty-four cords of wood.

June 22d.-We entered Lake Huron about breakfast time; the weather calm, and what the sailors call "greasy," the water darker than in Lake Erie, partly owing, no doubt, to the greater depth of water, and partly to the cloudy sky. The dark sullen water, and the unbroken line of forest, retreating on either hand as we issued

from the straits, gave a kind of grim majesty to this lake, by contrast to those we had left. Many sea-gulls about. Land in sight on the left all day, except in crossing Saginaw Bay.

On entering Lake Huron, we began to feel that we were getting into another region. Canoes of Indians about; the weather cool morning and evening, and the vegetation northerly, the pine family having a decided preponderance in the landscape. We might be said to have left the summer behind at the St. Clair, for thenceforth there was hardly a day during some part of which a fire was not necessary for comfort.

Just before sunset, when the sun was three or four degrees high, we noticed in the opposite quarter of the heavens, rays of light converging towards a point apparently as much below the horizon, as the sun was above. It had the appearance of a cloudy sunrise. We afterwards saw the same thing in the St. Mary's River; and it may be remarked, in both cases before rain."

June 23d.-Arrived at Mackinaw early in the morning, and landed on the wharf in a shower. We had been about eighty hours on the way from Buffalo, a distance of 663 miles, and we were vexed to hear that the weekly steamer for the Sault had left the evening before, and that if we had taken the other boat, which started punctually a couple of hours before us, we should have been in time.

We landed on the little wooden wharf in face of a row of shabby cabins and stores, with "Indian curiosities" posted up in large letters to attract the steamboat passengers during the brief stop for fish. Over their roofs appeared the whitewashed buildings of the Fort stretching along the ridge. The inhabitants of the place, looking down upon us from all sides, as from the lower benches of a theatre, soon perceived that we had not departed with the steamer, and we were soon plied with invitations to the two principal lodginghouses. From previous experience, I advised the "Mission House," and thither we went.

On the beach some Indians were leisurely hauling up their canoes, or engaged upon their nets, regardless of the rain. The Professor was soon in the midst of them, and bought white-fish and large pike,

See a notice of a similar phenomenon by Bory St. Vincent, in Goethe's Farbenlehre: [Entoptische Farben, cap. XXXI.]

An

which had been taken with nets or lines set the night before. excellent breakfast (at which white-fish figured,) and comfortable rooms, showed that the character of the "Mission House" was still

kept up.

It continued to shower at intervals during the day, but this did not prevent us from seeing the Natural Bridge, with its regular arch, ninety feet high, rising on the border of the island, the huge conical rock called the "Sugar Loaf," the Fort, &c. I do not know whether any of the party visited the cave where Alexander Henry was concealed by his Indian friend during the massacre of the English-as I did on a former occasion, when, bye the bye, I found a fragment of a human skull among the rubbish on the floor of the cave, attesting the correctness of that part of Henry's narrative.

The wet weather was not unfavorable to vegetation, which is luxuriant on the island, though the trees, (maple and beech,) are of small size, this latitude being nearly the northernmost limit of the latter. The flowers were beautiful; the twin-flower, (Linnæa borealis,) so fine that I thought it must be another new species; then the beautiful yellow ladies' slipper, Lonicera, and Cynoglossum.

The island is of a roundish form, two or three miles in diameter. On the N.E. the crumbly lime-cliff rises abruptly from the water to the height of a hundred feet or more; but on the south there is a sloping curve of varying width between the bluff and the beach.

The village lies on this slope, a single street of straggling logcabins and ill-conditioned frame houses, parallel with the beach, and some of a better class standing back among gardens at the foot of the bluff. On the edge of the bluff, which rises abruptly from the slope at the distance of some three hundred yards from the Lake, stands the Fort, a miniature Ehrenbreitstein, with a covered way leading down the face of the bluff.

We were disappointed at finding only three or four lodges of Indians here. In August and September (the time for distributing the "presents," there are generally several hundreds of them on

the island.

Notwithstanding the rain, the Professor, intent on his favorite science, occupied the morning with a fishing excursion, in which he was accompanied by several of the party, most of them pro

tected by water-proof garments, while he, regardless of wet and cold, sat soaking in the canoe, enraptured by the variety of the scaly tribe, described and undescribed, hauled in by their combined efforts. Not content with this, he as usual interested and engaged various inhabitants of the place to supply him with a complete set of the fishes found here.

With a view of indoctrinating those of us who were altogether new to ichthyology with some general views on the subject, he commenced in the afternoon, scalpel in hand, and a board well covered with fishes little and big before him, a discussion of their classification:

"These fishes present examples of all the four great divisions of the class. This pike, (Lucioperca americana,) belongs to those having rough scales and spinous fins. The rays of the first dorsal, and the anterior ones of the ventrals and the anal are simple and spinous; the other rays are divided at the extremity, and softer. The scales are rough and remarkably serrate. These are the CTENOIDS. They have five sorts of fins, viz: the dorsal, caudal and anal, which are placed vertically in the median line, and can be raised or depressed, and the ventral and anal, which are in pairs. In the Ctenoids the ventrals are placed immediately below the pectorals, though fishes having this arrangement of fins do not all belong to this division. There are but two families of Ctenoids found in fresh water the Percoids and the Cottoids; the former are characterized by having teeth on the palatal and intermaxillary bones, but none on the maxillary. Also by a serrate preoperculum and by the spines on the operculum. Of this family are the genera Perca, Labrax, Pomotis, Centrarchus, &c. The fish before us belongs to the genus Lucioperca. They have a wide mouth and large conical teeth, like the pickerels, and two dorsals. There are two species in Europe and two in the United States. This is L. americana; its color is a greenish brown above, with whitish below, and golden stripes on the sides. On opening the fish we find the heart very far in front, between the gills, and consisting of a triangular ventricle, a loose hanging auricle, and a bulbous expansion of the aorta. All the Percoids have three cœcal appendices from the pyloric extremity of the stomach. These probably take the place of a pancreas. Below is the air-bladder, which is a rudimentary lung. Above this are the ovaries, which extend from one extremity of the abdomen to the other. Behind is the kidney, extending along the spine.

.

This trout belongs to the CYCLOIDS.

In this division there are only

two families which have spinous rays in their fins, (the tautog and the mackerel.) We have before us specimens of two families of Cycloids.

1. Salmonidæ. Distinguished by having the intermaxillary and upper maxillary in one row, which seems to me to indicate the highest rank in the class of fishes. They all have a second dorsal, of an adipose structure. The anterior dorsal and the ventrals are in the middle of the body. Genus Salmo characterized by teeth on every bone of the mouth and on the tongue. There is but one genus in the class of fishes that has teeth on more bones than the salmon. In no genus are the species more difficult to distinguish. Sixteen species have been described as belonging to Europe, which I have been obliged to reduce to seven. The same species presents great variety of appearance, owing to difference of sex, of season, food, color of the water in which they live, &c. In this country I have examined two species, the brook trout, (S. fontinalis,) the spawning male of which has been improperly separated as S. erythrogaster; and the present species, the Mackinaw trout, S. amethystus of Mitchill. Dekay has described a variety of this species, as S. affinis. In this species the appendices pylorici before spoken of are very numerous. The small intestine arises from the lower extremity of the stomach, and curves only twice throughout its length. The gall-bladder is very large: the liver forms one flat mass; the ovaries and kidney extend along the whole spine. All this family spawn in the autumn. (2.) Cyprinidae. Like the salmons they have the ventral and dorsal fins in the middle of the body, but no adipose dorsal. Branchiostegal rays, three. Upper maxillary forming another arch behind the intermaxillary. Teeth only on the pharyngeal bone behind the gills, at the entrance of the oesophagus. No pyloric appendices. Intestine long and thin, as in all herbivorous fishes. Air-bladder transversely divided into two lobes, communicating by a tube with the intestinal canal.

"This family is the most difficult one among all fishes. As yet there is no satisfactory principle of classification for them. I have studied them so attentively that I can distinguish the European species by a single scale; but this not from any definite character, but rather by a kind of instinct. Prof. Valenciennes, a most learned ichthyologist, has lately published a volume on this family, in which he distinguishes so many species, and on such minute characters, that I think it now almost impossible to determine the species, until all are well figured.

"Here are specimens of two genera: (a) Leuciscus, with thin lips; only one species here, an undescribed one characterized by a brownish stripe above the lateral line. (b) Catostomus, with very thick lips and prominent snout."