ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 35 



bite oft* the leaves they eat, and never put their hands to their 

 mouths. Although they move about on the branches back downwards, 

 they do not sleep in this position. 



Theory of Pentadactyl Limb.*— A. N. Sewertzoff has studied the 

 development of the limb in a number of reptiles and amphibians, such 

 as Ascalobotes fascicularis and Triton cristatus, and has been led to thi 

 conclusion that the pentadactyl limb may be traced back to a broad 

 horizontal fin attached by a broad base to the lateral body wall. 



Relation of Size and Structure of Intestine to Diet.t— P. Reviliiod 

 finds that the average relation of length of intestine to length of body 

 in the adult rat is 6 : 1 ; this ratio is affected by age, sex, and diet ; in 

 25 males it was 5*77 : 1 ; in 20 females 6*2:1; in the new-born the 

 ratio is 4' 17 : 1 ; at one month it is 6*49 : 1 ; at three months 6:1. 



The form of the villi changes in the first two months from 

 cylindrical to high and narrow, and then to broad and semilunar. 

 Vegetable food has a mechanical influence on length, resulting in slight 

 elongation. Animal food has a chemical influence on length, resulting 

 in great elongation. With a milk diet the intestine is reduced in 

 diameter and length, and the villi have a form similar to that seen 

 during lactation. 



The short intestine of Carnivores is the result of a very slow 

 functional adaptation. The long intestine of Herbivores is due to the 

 permanent mechanical effect of the insoluble residue of the food. 



Haemoglobins of various Vertebrates.:]: — E. T. Reichert and 

 A. P. Brown find that the crystals of haemoglobin, from species of Felis, 

 are quite different from those of C'anis. There is even specificity in the 

 hamioglobin-erystals of a species, e.g. difference in the angles. In sonic 

 species the oxyhemoglobin is dimorphic, or even trimorphic. This is 

 an interesting contribution to the conception of chemical specificity. 



Labyrinth of the Ear.§ — Albert A. Gray continues his careful 

 study of the structure of the labyrinth in Vertebrates. He gives an 

 account of the membranous labyrinth of the monitor, the emu, the rhea, 

 the penguin, the echidna, and discusses the relationships of the aqueducl 

 of the perilymph, the perilymph recess, and the round window to one 

 another, and_to the cochlea, and shows how the last stage— in Primates- 

 may have been reached from the Reptilian condition. 



Moulting in Lizards.j| — H. L. Brunner has studied the mechanism 

 of moulting in the head of lizards. The veins and blood sinuses of tin ■ 

 head are concerned. Special muscles distend the sinuses and raise the 

 venous blood-pressure. One of these muscles (m. constrictor vena' 

 jugularis interna?), invests the jugular where it passes from the head 

 into the neck; a second (m. protrusor oculi), lies behind the orbit, in 

 close relation to the large orbital sinus. During the moulting the 



* Bull. Soc. Imp. Moscow (1907) pp. 1-430 (C pis.). 



t Rev. Suisse Zool., xvi. (19J8) pp. 241-319 (1 pi.). 



t Proc. Amer. Phil. Soc, xlvii. (1903) pp. 298-301. 



§ Proc. Roy. Soc, Series B, lxxx., No. B 543 (1908) pp. 507-28 (2 pis). 



|| Proc. Indiana Acad., 1907 (published 1908) p. 61. 



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