THE MIcROSCOPE. 61 
to occur with experienced observers. At the close of a recent 
article on this subject by Dr. Up de Graff, of Elmira, in which 
he assumes that the new standard of z#so of an inch is nearer 
correct than the old s#cc of an inch, he says: “ Would not the 
prevailing difference in size still exist—as shown by Gulliver— 
when measured by Mr. Vorce? If not, why not?” Mr. Hitch- 
cock replies: “ Certainly the relative sizes would be the same.” 
I am not so sure about this conclusion. We know more to- 
day about the human blood, because we have better instru- 
ments, and because we study it far more, than Gulliver did. 
Gulliver studied the blood of many animals. We are princi- 
pally engaged, it would seem, in studying the blood of man. 
Study the blood of the dog, the horse, and the pig, as thoroughly 
as human blood has been studied, and perhaps the ratio may be 
changed. It does not seem to me that “certainly ” the rela- 
tive sizes would be the same. Here is a little proof on that 
point. Gulliver said: Man, soc, Dog, siz, Hog, 4x. Now 
Woodward says: “The mean average of 1,766 corpuscles of 
human blood ranged from .000,309 to .000,543 of an English 
inch. Nearly the same number of corpuscles of dog’s blood 
gave .000,296 to .000,340 of an inch.” Is not the proportion 
changed here ? 
Elsberg says the mean diameter of the red corpuscle of 
man is .0O75 mm. 
Welcker says the average diameter of the corpuscles of the 
cat is .0065 mm. 
Has the ratio been retained here by modern observers ? 
Welcker says the mean diameter of the corpuscles of the 
cat is .0065 mm., and of the rabbit .0069. Gulliver said they 
were: Cat, zioz; Rabbit, s¢c7. Has the ratio been maintained ? 
We assert that—‘ If Mr. Vorce should apply his microme- 
ter to the human corpuscles and find them to measure 700 of an 
inch,” instead of ssc, he would not necessarily “ find also, by 
the same rule, the pig’s to measure ico of an inch.” The rela- 
tive sizes need not necessarily be the same. So now I will 
“venture an opinion.” It is this: As soon as microscopists pay 
as much attention to the blood of the lower animals as they 
have already given to human blood, it will be found that the 
relative sizes of the red blood-corpuscles as given by Gulliver 
are incorrect. 
