44 PROGRESS OF MICROSCOPICAL SCIENCE.  [Monthis Microscopten 
eleven times, and their width from twice to five times.” The latter part 
of this quotation I find is copied verbatim into nearly all the standard 
works on anatomy and physiology extant. But instead of an increase 
in length of seven to eleven times, the above figures indicate an increase 
of jifiy to eighty-three times, and the breadth from two to three times. 
Now, which of these widely-ditfering statements is the correct one is 
not easy for the student to decide. Therefore if some reader would 
set him right he would be obliged. 
Zoological and Physiological Import of the Size of the Red Corpuscles 
of the Blood.—In a memoir on this subject by Professor Gulliver in 
the part just published of the ‘ Proceedings of the Zoological Society,’ 
some notewo1thy observations occur. His discoveries show that the 
largest red corpuscles of the blood yet known in several genera of one 
order of Mammalia are found in the order Edentata, and the smallest 
in the order Ruminantia. He gives figures of them in Orycteropus 
(the Aardvark of South Africa), in the Napu Musk Deer (T’ragulus), 
and in the true Musk Deer (Moschus moschiferus). Thus the orders in 
question can be at once distinguished simply by the size of the red 
blood-corpuscles. And, still further, several families of this or that 
order may be thus diagnosed; of which he gives a remarkable and 
curious proof in the blood of Moschus. When this was submitted to 
his examination by Professor Flower, Mr. Gulliver at once pronounced 
that, though the corpuscles had the ruminant character, they could not 
belong to an animal of the same genus or family as the old Moschus 
(now Tragulus), and his figures show the differences in point. He 
confirms the rule, long since discovered by him, that there is a rela- 
tion, ceteris paribus, between the size of the red corpuscles and that 
of the species of animal in a single family of Mammals; though there 
is no such relation, as Hewson had shown, in species of different 
orders,—the Mouse and Horse, e.g. As to the comparative smallness 
of the red corpuscles in the smaller species of a family of Mammals or 
the class of Birds, he concludes that it is a provision for an increase 
of the sum of the surface of the blood-disks, as carriers of oxygen in 
the service of respiration and the production of animal heat, since the 
aggregate surface of a given bulk of them will be multiplied by their 
minuteness, and thus the comparatively greater loss of heat by the 
smaller animals will be compensated, as more fully explained in the 
report of his Lecture IX., in the ‘ Medical Times and Gazette,’ Janu- 
ary 17, 1863, and in another of his lectures abstracted in ‘ Scientific 
Opinion, December 8, 1869.. The doctrine that the size of the red 
corpuscles has relation to the food of the animal—that the corpuscles 
are largest in the omnivorous species—he utterly rejects, because, 
among other reasons, the corpuscles are not larger in the omnivorous 
Pig than in the phytivorous Rhinoceros, Tapir, and Ass, and are as 
large in the carnivorous Ursine Dasyure as in the omnivorous Pera- 
meles. The whole memoir abounds in the results of Professor Gulli- 
ver’s researches on the sizes of the red corpuscles of the blood, and 
affords remarkable proof of the value of microscopical observations in 
systematic zoology. The comparative descriptions and figures in this 
respect are both interesting and new as regards Tragulus, Moschus, and 
