22 Field Museum of Natural History — Zoology, Vol. XI. 



where in Man they measured only 3 o'o and even less. Under such 

 conditions an expert depending upon size alone * could not readily 

 distinguish them from those of a Dog, or an Ape. The following 

 measurements of red corpuscles of various mammals are selected 

 from those given by Prof. G. Gulliver (Proc. Z06I. Soc. Lond., 1845, 

 p. 96; lb., 1862, p. 102): Elephant 27^0, Man 3^^oo, Ape 31 it, 

 Beaver 33^25, Wolf 3(i\ui, Tiger i-his, Bat -rsV^, Horse kvoo, Sheep 

 :5" 3^0 , Red Deer n o\) , Musk Deer 12000. 

 Stomach and Intestinal Canal — The passage through which food passes 

 from the mouth to the stomach is called the oesophagus, and in the 

 majority of mammals the stomach consists of a single chamber, 

 although varying somewhat in shape in different species. Sometimes 

 it is divided into a series of chambers, as in the Ruminants, in 

 which group the stomach contains at least three and usually four 

 sections; or in the Cete, where the number varies from 3 to 8. 



^ 



I, Stomach of Mouse. (After Wiedersheim.) 2, Common type of alimentary canal in many 

 mammals. 1, large intestine; s, small intestine (much abbreviated) ; c, coecum; r. rectum; o, oesophagus. 

 (After Flower and Lydekker.) 3. Portion of intestine, showing coecum, of Proboscidion Shrew, c. 

 coecum. (After Owen.) 4, Common type of coecum in Man. c, coecum; v, vermiform appendix. 

 (After Gray.) 



At the lower end of the stomach is what is called the pylorus, 



where it joins the small intestine, which in turn continues to the 



large intestine or colon which ultimately ends at the rectum. At 



the juncture of the large and small intestines there is usually a 



blind sac or pouch, known as the caput ccecum coli, but which has 



popularly been abbreviated into '^ccBcum^' (see illustration). This 



organ varies greatly in different mammals. In some species it is 



merely a slight bulge or apparently absent, while in others it is 



largely developed. Ruminant animals have large caecas, but in the 



Cat tribe it is but slightly indicated. The Phalanger, Trichosurus 



vulpecula, has a caecum fully one-fifth as long as the small intestine. 



In Man the caecum is present in the form of a sac two or three 



* The serological test (based upon the chemical character of the blood serum) is 

 of value in most diagnoses, but cannot be depended upon to distinguish the blood 

 of Man from that of some of the higher Apes. 



