CHAP. XXVII.] 



THE BLOOD-CORPUSCLES. 



299 



The corpuscles of the goat are very small, ^ ^ of an inch in diameter. 

 The largest corpuscles in Mammalia are found in the elephant ; they measure, 

 according to Gulliver, ^3 of an inch in diameter. The Camelidse offer a re- 

 markable exception to the circular form of the blood-corpuscle of Mammalia. 

 In these animals it is oval, as first pointed out by Mr. Gulliver, with a long 

 diameter of from 3T ! 5i5 to ^ of an inch, and a short diameter of 58 foj to rf n ; in all 

 other respects, however, these corpuscles agree with those of other mammals. 



In Birds the corpuscles are oval in shape ; they have a very distinct nucleus, 

 which is much smaller than the corpuscle itself. The long diameter of the 

 blood-corpuscle of Birds ranges between 73^$ and 5003 of an inch, and the short 

 diameter from 3i fo, to ,^, of an inch. (Figs. 175, 181, 183). 



Fig. 175. 



Fig. 176. 



<$ 



B 



Red corpuscles of pigeon'3 blood magni- 

 fied 400 diameters. A. Red particles unal- 

 tered, with two or three colourless particles. 

 B. Treated with acetic acid, which develops 

 the cell-wall and nucleus more clearly. 



Blood-corpuscles of the common frog. Mag- 

 nified 400 diameters. A. In serum, a. Fully 

 developed corpuscle, b. Nucleus with pate cell- 

 wall and clear contents, c. Colourless cor- 

 puscle. B. Treated with acetic acid. 



In Reptiles the red corpuscles are of an oval shape, with a distinct and 

 large nucleus (Fig. 176). The long diameter of the corpuscle has a range of 

 from , to T ^ B of an inch, the short diameter ranging between 7 ^j to ^ of an 

 inch. Among these are to be found the largest known blood- corpuscles, as 

 those of the proteus and of the syren. 



Fig. 177. 



Fig. 178. 



Red corpuscle of fishes: a. Lamprey. 

 b. Skate. (After Wharton Jones.) 



Blood-corpuscles of the crab. A. Granule 

 cells. A. Nucleated cells. (After Wharton 

 Jones.) 



In Fishes, the red corpuscle is oval in most of the genera, and possesses a 

 distinct nucleus (Fig. 177, b). In the lowest cartilaginous fishes, as the lamprey 

 and the myxine, however, it returns to the circular and biconcave form of the 

 Mammalian red corpuscle (Fig. 177, a). This remarkable fact was first pointed 

 out by Professor R. Wagner. Mr. Wharton Jones has shown that it contains 

 a nucleus, which cannot be detected in the red corpuscles of Mammalia, 



x 2 



