600 



VERTBBRATBD ANIMALS. 



sions of some of the most interesting examples of the Red blood- 

 corpuscles, in the four classes of Vertebrated Animals, expressed 

 in fractions of an inch. Where two measurements are given, 

 they are the long and the short diameters of the same corpuscle. 



MAMMALS. 



Man 1-3200 



Dog, 1-3542 



Whale, 1-3099 



Elephant, 1-2745 



Mouse, 1-3814 



Camel, 1-3254, 1-5921 



Llama, 1-3361, 1-6294 



Java Musk-Deer, .... 1-12325 



Caucasian Goat, 1-7045 



Two-toed Sloth, .... 1-2865 



Golden Eagle, 

 Owl, . . . . 

 Crow, . . 

 Blue-Tit, . . 

 Parrot, . . . 



Turtle, . . 

 Crocodile, . 

 Green Lizard, 

 Slow-worm, 

 Viper, . . 



1-1812, 1-3832 



1-1830. 1-.3400 



1-1961', 1-4000 



1-2313, 1-4128 



1-1898, 1-4000 



Ostrich, . 

 Cassowary, 

 Heron, . 

 Fowl, . 

 Gull, . 



KEPTILES. 



1-1231, 1-1882 

 1-1231, 1-2286 

 1-1555, 1-2743 

 1-1178, 1-2666 

 1-1274, 1-1800 



Frog, . . 



Water-Newt, 



Siren, 



Proteus, 



Lepidosiren, 



1-1649, 1-3000 



1-1455, 1-2800 



1-1918, 1-3491 



1-2102, 1-3466 



1-2097, 1-4000 



1-1108, 1-1821 



1-814, 1-1246 



1-420, 1-760 

 1-337 



1-570, 1-941 



Perch, . 



Carp, 



Gold-Flsh, 



1-2099, 1-2824 

 1-2142, 1-3429 

 1-1777, 1-2824 



Pike, . 

 Eel, . . 

 Gymnotus, 



1-2000, 1-3555 

 1-1745, 1-2842 

 1-1745, 1-2599 



Thus it appears that the smallest red corpuscles known are those 

 of the Mush-Beer ; whilst the largest are those of that curious 

 group of Batrachian (frog-like) Eeptiles which retain their gills 

 through the whole of life ; and the oval blood-disks of the Proteus, 

 being above 36 times as long as those of the Musk-Deer, and pro- 

 bably at least 20 times as broad, would cover no fewer than 720 

 of them. 



415. The "colorless" corpuscles are more readily distinguished 

 in the blood of Reptiles, than in that of ]\[an ; being, in the 

 former case, of much smaller size, as well as having a circular 

 outline (Fig. 314, c) ; whilst in the latter, their size and contour 

 are nearly the same, so that, as the red corpuscles themselves, 

 when seen in a single layer, have but a very pale hue, the de- 

 ficiency of color does not sensibly mark their difi'erence of nature. 

 It is remarkable that, notwithstanding the great variations in the 

 sizes of the red corpuscles in different species of Vertebrated ani- 

 mals, the size of the "colorless" is extremely constant through- 

 out, their diameter being seldom much greater or less than 

 l-3000th of an inch in the warm-blooded classes, and l-2500th in 

 Reptiles. Their ordinary form is globular; but their aspect is 

 subject to considerable variations, which seem to depend in great 

 part upon their phase of development. Thus in their early state, 

 in which they seem to be identical with the corpuscles found 

 floating in Chyle and Lymph, the cell-Avall can scarcely be dis- 



