the American Manatee and Behiga leucas. 173 



In a paper by my father " On the Sizes and Shapes of the 

 Red Corpuscles of the Blood of Vertebrates," published in 

 the ' Proceedings of the Zoological Society,' June 15, 1875, 

 there occurs the following remark : — '' Much larger red blood- 

 corpuscles than those of the human species may be expected 

 in the most gigantic marine Feraj and Cetacea. The largeness 

 of the corpuscles in Orycteropus was truly predicted long before 

 they were ever examined ; and we may well suppose that they 

 were larger in the huge extinct Edentates than in any existing 

 mammal. It would be interesting and probably instructive 

 to examine the corpuscles of the Sirenia." 



Some time back, in a communication to my father, Prof. 

 Garrod stated that he had examined the blood of the indivi- 

 dual of this species which died in the Zoological Gardens, 

 and found the corpuscles to be of large size. He has since 

 published measurements of the corpuscles in the Zoological So- 

 ciety's ' Transactions' for Oct. 1, 1877, where he says, " In 

 the Manatee the diameter of the largest corpuscles reaches 

 YT^H) o^ ^^ inch, others being considerably smaller." As an 

 independent confirmation of his observation that the corpuscles 

 of this animal are of a large size, and at the same time an ex- 

 pression of opinion on my father's and my own part that they 

 are considerably larger than he supposes, I venture to think 

 that this observation is not without value. 



I have submitted a specimen of the blood to my father, who 

 agrees with me in making the average size of the corpuscles 

 -^xw^ ^^ ^^^ English inch. It is well known that in the same 

 species, and in the same individual of that species, the red 

 corpuscles are found to vary within certain limits ; and it is 

 only by careful and constantly repeated observations that the 

 prevailing or mean size can be estimated. It is this size only 

 which is given here. 



Whilst* I was watching the dissection of the white whale 

 [Beluga leucas) which recently died in the aquarium. Dr. 

 Murie was kind enough to provide me with specimens of the 

 blood. Knowing, from my father's measurements of the cor- 

 puscles in other species of Cetacea, that they would prove to 

 be large in this animal, it was interesting to obtain a specimen 

 of the blood for comparison with that of the Manatee. It 

 requires more than a superficial glance to detect a difference 

 in size in the red corpuscles of the two animals. But in the 

 Beluga, though the corpuscles are, without doubt, superior in 

 size to those of any of the three cetaceans mentioned by my 

 father, they are decidedly inferior to those of the Manatee. 

 Their average diameter is -g^o inch. The corpuscles of this 

 cetacean, then, rank next in size amongst Mammalia to those 



