RED GLOBULES OF THE BLOOD. 251 



ing matter is identical with that in the human species. Even in Am- 

 phioxus, a kind of fish of very low grade of organization, which was 

 long regarded as exceptional in this respect, the existence of faintly 

 colored globules has been demonstrated of late years. That th'e coloring 

 matter of these globules consists of hemoglobine has been demonstrated 

 in such different animals as the dog, fox, cat, horse, sheep, pig, lion, 

 cougar, baboon, bat, hedge-hog, rat, guinea-pig, squirrel, mole, goose, 

 pigeon, lark, owl, crow, lizard, python, tortoise, frog, carp, perch, her- 

 ring, and pike. It has been discovered, in all, in 22 species of mam- 

 malians, 7 birds, 5 reptiles, and 12 fish; and has been found to exist in 

 every species of vertebrate animal which has been examined for that 

 purpose. Even in several invertebrate species where the blood is of a 

 red color, although it exhibits no distinct globules, it has been found to 

 contain hemoglobine in a state of solution. Preyer found that the red 

 circulating fluid of the earthworm, when examined by the spectroscope, 

 yielded a spectrum with two absorption bands identical with those of 

 human hemoglobine. It has also been discovered in the blood of the 

 pond-snail, the horse-leech, and the fresh-water shrimp. 



But although in all these cases the red globules contain the same 

 coloring matter, they present, in different animals, variations of form, 

 size, and structure, which are more or less characteristic of the different 

 classes, families, and species, to which they belong. 



In the mammalians, or warm-blooded quadrupeds, the red globules 

 of the blood have without exception the same homogeneous structure as 

 in man. They have also invariably the same disk-like figure, with a 

 circular outline, except in the species belonging to the family of the 

 camelidse (camel, dromedary, lama), where the disks have an oval form. 

 The size of the red globules in the mammalians varies much in extreme 

 cases; the smallest known being those of the Java musk-deer, an animal 

 not larger than a rabbit, which have a diameter of 2.50 mmm., while the 

 largest are those of the elephant, which measure 9.20 mmm. The rela- 

 tive size of the globules, however, in different species, does not con- 

 stantly correspond with that of the animal itself; since those of the cat 

 are larger than those of the sheep, and those of the rabbit larger than 

 either. The following list gives the size of the red globules in various 

 species of mammalians, according to the measurements of Gulliver and 

 Welcker: 



DIAMETER OF THE CIRCULAR RED GLOBULES OF MAMMALIANS, 



in micro-millimetres. 



. . 7.35 Horse .... 5.43 



f>og . 7.30 Sheep .... 5.00 



Wolf .... 6.94 Red deer . . . 5.00 



Rabbit . . . 6.90 Goat .... 4.10 



Cat .... 6.50 Elephant . . . 9.20 



Fox .... 6.10 Two-toed sloth . . 8.93 



Ox .... 5.95 Java musk deer . 2.50 



