1875.] RED BLOOD-CORPUSCLES. 483 
ference is swollen, so as to produce triangular, oval, or formless pits 
towards the centre. In the Tables of Measurements only the regular 
blood-disks are noted. Of the Apyrenzemata the Camels (figs. 37- 
41) alone have oval red blood-corpuscles ; but these, as before men- 
tioned, conform in all other respects to the apyreneematous type; and 
a few subrotund or circular disks may occur among the prevailing 
oval ones. In some Cervide the corpuscles (fig. 42) assume fusiform, 
lanceolate, crescentic, and irregularly polygonal and other angular 
forms, as originally figured on page 329 of the ‘ London and Edin- 
burgh Philosophical Magazine,’ Nov. 1840; but with these are 
mixed a few red corpuscles of the usual circularity, which only were 
measured for the Tables. 
Size of the corpuscles.—They are the smallest in the vertebrate 
subkingdom ; and the smallest of all occur in the Ruminants (figs. 29- . 
34), especially in the Tragulide (figs. 29-31) ; and thus this family 
may be distinguished from all other Vertebrates, not even excepting 
Moschus (Proc. Zool. Soc., Feb. 10, 1870, fig. 2), which was formerly 
confounded with Zragulus, and of which the anatomy has been de- 
scribed by Professor Flower in the ‘Proc. Zool. Soc.’ March 16, 
1875. Comparative views of the corpuscles of these two genera are 
engraved to a scale in the same ‘ Proceedings,’ Feb. 10,1870. Since 
then, using Powell and Lealand’s ;4, objective, I could detect no 
difference between these red blood-corpuscles of Moschus moschiferus 
and Cervus nemorivagus (fig. 32), while the comparative smallness 
of those of Tragulus (figs. 29-31) was remarkable and significant. 
The largest corpuscles in the class belong to the Elephants (fig. 23), 
great Edentates (fig. 47), and pinniped Fere (fig. 14); in some of 
which, as the Walrus (fig. 14), the Elephants (fig. 23), the Great 
Anteater (fig. 47), the Two-toed Sloth (fig. 48), and the Ardvark 
(Proc. Zool. Soc., Feb. 10, 1870, fig. 4), the corpuscles are as large 
as in a few Birds (figs. 6] and 66). The Monotremata (fig. 52), 
Marsupialia (figs. 50 and 51), and Rodentia (figs. 43-46) have some- 
what large corpuscles, which in some Cetacea (fig. 20) are larger. 
Sometimes two sets of corpuscles occur in nearly equal proportions, 
one set about a third smaller than the other; this fact, though rare 
in most mammals, is not uncommon in the Squirrels. Of the Pachy- 
dermata the Elephants alone have the corpuscles larger than those 
of Man, and the smallest occur in the Horse (fig. 26); their com- 
parative largeness in such a small species as Hyraz (fig. 28) proclaims 
it, though arranged here, but an irregular member of this order. 
In the Fere or Carnivora there are great irregularities: while 
some of the largest apyrenematous corpuscles occur in this order, 
they are in many of its species smaller than in several Ruminantia. 
The families of Carnivora, according to the sizes of their red blood- 
corpuscles, would stand thus :—Seals (fig. 14), Dogs (fig. 15), Bears 
(fig. 11), Weasels (fig. 16), Cats (fig. 17), Viverras, Paradoxures 
(figs. 18 and 19). These sizes differ so much that by them alone 
Seals or Dogs may be easily distinguished from Viverras or Para- 
doxures ; while the same kind of diagnosis would be difficult, unless 
under the most favourable circumstances, and in some cases impos= 
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