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It would be interesting to carry the experiment further and see if a union of the Manx cat with one of her own race would result in restoring with the same regularity with which she lost it, the power to produce her own type. (Revue Scientif. T. 4, 1895.)

A case of Renal Abnormality in the Cat.-Anomalous condition of the renal organs and accompanying blood vessels was recently

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disclosed in a dissection in this laboratory. The accompanying diagram explains the phenomenon. The left kidney was a miniature of the right though functional. The dimensions of the right kidney in another subject of equal size as the specimen under discussion were found to be-length 3 cm., width 2 cm. and dorso-ventral thickness 15 mm.; the left os is natural being slightly smaller than this. The dimensions just given may be regarded as normal.

In the subject whose renal anatomy has been here figured, the measurements of the right kidney were as follows: length 4 cm. breadth 21 cm. and thickness (dorso-ventral) 19 mm., considerably above the normal as one would expect when the extremely small size of the left kidney is considered. The dimensions of the latter were as follows: length 12 mm., breadth 8 mm., and thickness or dorsoventral diameter 5 mm., less than one-third the dimensions of the right kidney. Upon hardening, staining and sectioning in the usual way the glomeruli and uriniferous tubules were found to be normal though, the presence of a small amount of fat in the kidney was noted. The histological condition of the kidney and the presence of the left ureter, which, though smaller than the right was clearly functional, proved that the left kidney was of value in the vegetative processes of the organism. The right renal artery (ra) was, as one would expect larger than the left (ra). The postcava (pc) in this cat was divided very far forward in the lumbar region to form the common iliac veins, causing the left

This variation

renal vein (rvi) to empty into the left common iliac. from the normal in postcaval structure is by no means uncommon. Letters in the figure, not referred to in the text are as follows: da. dorsal aorta, cax. cœliar axis, a. m. s. anterior mesenteric artery, rv. vein from right kidney, R1. right kidney, R. left kidney, ar. and ari. left and right adrenal bodies with accompanying veins. Il left and right common iliacs, ilmb. ilio-lumbar veins u ureters, urocyst urinary bladder.-F. L. WASHBURN, Biological Laboratory, University of Oregon.

Zoological News.-Mr. O. F. Cook has published a monograph of Scytonotus. He considers this genus to be the most specialized of the Polydesmid Myriapoda, basing his conclusion on its secondary sexual characters. He recognizes nine species as belonging to the genus. (Ann. New York, Acad. Sci., VIII).

A gigantic Cephalopod, supposed to be a new species of Architeuthis, was driven inshore on the eastern side of the bay of Tokyo. A description of it, illustrated with drawings, is published by K. Mitsukuri and S. Ikeda. It is characterized by shape of its fins and of its beaks, the unequal lengths of the sessile arms, and other minor details. (Zool. Mag., Vol. VII, 1895).

Prof. Gegenbaur has in the Morphologisches Jahrbuch for the year 1895, instituted a study of the clavicle and the elements adjacent to it and the scapular arch. He calls attention to the fact that there are two elements in the position of the former in Dipnoi, Crosopterygia and Chondrostei. He then shows that the element nearest the scapula is retained in some of the Stegocephalia, while the anterior and distal element is increased in length. He calls the former the cleithrum, and retains for the latter the name clavicle. The clavicle only remains in the existing order of Batrachia, and higher groups, while the cleithrum only remains in the higher fishes, beginning with Lepidosteus and Amia.

According to Dr. Delisle the cranial capacity of the Orang-Outang averages 408 cubic centimeters. (L'Anthropologie Tome, VI, 1895.) Ranke's researches show that the weight of the human brain is much greater in proportion to the weight of the spinal cord than in any other vertebrate. (Correspondenzblatte).

Dr. E. Rosenberg publishes in the Morphologisches Jahrbuch for 1895, an investigation into the reduction of the number of the incisor teeth which is seen in the human species. He shows: first, that the loss of

the external incisor, which was first pointed out by Cope, and which has been observed independently by several others, is frequently observed in Europe as well as in America; second, that the loss of the first inferior incisor is also not very uncommon in Europe and that the final reduction of the inferior incisors, should it take place, will be by the loss of this tooth and not by that of the external incisor as in the superior series. He, therefore, believes that the ultimate formula of the incisive dentition in man will be It, and not I, as Cope left it.

ENTOMOLOGY.1

The Segmental Sclerites of Spirobolus.-The structure of the segments of Diplopoda has long been a morphological puzzle. On account of the possession of two pairs of legs they have in a general way been supposed to be double segments, that is, formed by the coalescence of two distinct embryonic or theoretical segments. Toward a morphological demonstration of this idea there has been little progress. Indeed, there are many facts which give grounds of suspicion as to its correctness. Among these may be noticed that the double footed state does not occur in the embryo at all, and that the segments which in the adult bear two pairs of legs either do not exist in the newly hatched larva or do not bear any legs at that stage, the newly hatched diplopod larva having but three pairs of legs, the posterior of which is attached to the fourth segment (at least in the Polydesmoidea). Moreover, all Diplopoda have apodous segments not differing otherwise from those which bear legs; also all Diplopoda have segments which bear but one pair of legs, and yet have not been found to be greatly different from the others. Growing Diplopoda acquire segments by intercalation in front of the last. The segment is added at one moult, the legs for it at the next. As the possession of two pairs of legs has been the occasion of the theories of duplex segments, these facts are the more relevant as objections, since more difficulties are introduced than are disposed of by the theories.

The existence of pluræ in the Oniscomorpha has long been known, and for a less period in the Colobognatha and Limacomorpha. In the other orders these elements of the segmental ring are so thoroughly coalesced or eliminated that their existence was theoretical until their

1 Edited by Clarence M. Weed, New Hampshire College, Durham, N. H.

discovory in Stemmatoiulus. In that form, however, the multiplicity of peculiar characters weakens the application of homologies to the other orders, unless these can be based on structural facts. It is thus a matter of interest that the existence of pleuræ in another Diplopod order can be affirmed.

Some weeks since in examining large African Spirobolidæ I noticed what seemed to be traces of pleural sutures. On mentioning this fact to Mr. F. C. Straub who was studying with me, he called my attention to a specimen of Spirobolus marginatus Say which proved to be very remarkable. Possibly it was collected just after moulting, before the sclerites had become coalesced, or it may have been merely an individual anomaly. At any rate, it had on each side an obliquely longitudinal white line across each segment above the pedigerous lamina ̧ indicating a pleural element about as broad as the lamina. That this is the pleural suture seems very probable, on theoretical grounds and more so that on the surface a special striæ followed the line of white.

What is more remarkable, this line was met above by two others which were transverse, dividing the segment into three subequal parts. These two lines extended completely over the animal, the space between them being somewhat greater above. There is also a median longitudinal suture, and a lateral just below the pore, thus dividing the dorsal portion of the ring into twelve subequal parts. The posterior of the transverse sutures follows the depression found in the segments of Spiroboli and usually called "the suture" in descriptions. The anterior line and the median line are indicated by minute differences in the sculpture, which would not have been noticed had not the white line drawn attention to them. It should be added that the lighter color was not due to anything inside or outside the segmental wall, but was in the wall itself and clearly indicated some structural difference. The phenomenon was exhibited by the anterior and middle segments of the body, becoming indistinct caudad. In all cases the pattern was the same; the whole series of lines could be made out on many segments, and there were no other similar lines or discolorations. The lines were not straight if examined under a microscope, even the median showing minute irregularities. Median sutures are known in four or five of the Diplopod orders and hence may reasonably be expected in all.

Had only the median line been marked as related, there would have been no hesitation in supposing that a median suture was indicated. Theoretical considerations only stand in the way of the reasonable presumption that the other exactly similar lines indicate sutures. If such an interpretation is allowed we are brought to the position that

the segmental ring of Spirobolus consists of sixteen sclerites; twelve dorsal, two pleural and two ventral or pedigerous laminæ. It will be seen that only the last tend to indicate a transverse division of the segment, and in no Diplopod as yet has there been shown a transverse suture carried around the segment and dividing it into two parts. Only the legs and the parts necessarily connected with them, such as the pedigerous lamine and nerve ganglia are duplicated. Even in the Oniscomorpha, Limacomorpha and Colobognatha where the pleuræ are most distinct, there is not the slightest indication that they were ever divided, and as they are the elements to which the pedigerous lamina are next related, their evidence is more important than any drawn from the dorsal parts of the segment.

There is another way, however, in which a diplopodous animal might be developed from a monopodous ancestor. Alternate segments may have been suppressed, while the corresponding legs have been preserved. For such a supposition we have the analogy of the Chilopoda, where the pedigerous segments alternate with more or less rudimentary segments. In this case, however, the legs have been lost, that is, we must suppose so if we claim the analogy. Such a theory, while no more fantastic than the other, is probably no nearer the truth. After theoretical explanations have been exhausted we may, perhaps, learn that the double-footed condition is a peculiarity of this group of animals, not explainable by any general morphological considerations, but sui generis, after the manner of the branched segmental appendages of the Crustacea.-O. F. CoOK.

Secretion of Potassium Hydroxide.-Mr. O. H. Lalter has some further notes on the secretion of potassium hydroxide by Dieranura vinula and similar phenomena in other Lepidoptera. He finds that the imagines of eight species secrete from the mouth an alkaline fluid on emerging from the pupa. The three species of Dicranura wear what is called a shield, derived from the pupa case as they emerge, and they subsequently remove it by their legs. He finds that the strength of the solution in D. vinula is about 1.4 grm. of potassium hydroxide in every 100 ccm. of liquid. The mesenteron of the same species develops an anterior dorsal diverticulum for storage of the alkali during pupal life.-Journal Royal Mic. Society.

Lake Superior Coleoptera.-Mr. H. F. Wickham publishes3 an admirable list of Coleoptera from the southern shore of Lake Supe

2 Trans Ent. Soc. Lond., 1895, 399-312.

3 Proc. Davenport Acad. Nat. Science, VII, 125–169.

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