THE CLASSIFICATION OP TfiE VEETEBEATA. 189 



that, like Owen, but/ unlike certain more recent classifiers, he lays 

 a full and just weight on the distinction between the cold-blooded 

 and the warm-blooded group of animals. This distinction is 

 smothered if we, with Huxley, join together a part of the reptiles 

 with the birds under the name of " Sauropsida." I have ventured 

 to point out that cold-blooded animals alone secrete physiological 

 venous pigments and textile fibres, whilst in the warm-blooded 

 group (biixls and mammals) the enei^gy which would be required 

 for the elaboration of such products serves for mainlaiuing the heat 

 of the system. It is a very interesting fact that in the Ornitho- 

 rJiynclms, the only mammal which has the power of secreting a true 

 venom, the temperature of the blood is about 15 degrees lower 

 than that of other mammals. Hence, to write cold-blooded and 

 warm-blooded animals in oiae and the same group seems to be a 

 grave error. It is very satisfactory to find the author giving his 

 opinion that Natural selection has nothing to do with Evolution, 

 and that to raise an organism to a higher plane we must have 

 some inherent power and not any mere external agency. Whether 

 such agency is temperature, atmospheric pressure, moisture, diet, 

 or the rivalry of co-existing species, is not the capital point. 

 Many writers do not distinguish between evolution and variation. 

 1 am much gratified to find to what extent Professor Cleland does 

 justice to the late Professor Owen, whom I have the honour of 

 considering as ray old master, some of whose contemporaries and 

 successors, though they may have spoken lightly of his attain- 

 ments, have been reaping the harvest of what he sowed, although, 

 at times, failing to accord him credit for what he has done. 

 The meeting was then adjourned. 



COMMUNICATIONS EECEIVED IN REGARD TO TEE 

 PRECEDING PAPER. 



Professor H. W. Parker (United States) writes : — 

 I have read carefully and with much interest the paper by 

 Professor Cleland — with the more interest because for ten years I 

 used his compact manual of animal physiology as a text-book in 

 my college classes. It seems to me that he makes out his case 

 convincingly, even in so brief a discussion ; and it is refreshing to 

 find that scientific progress with its attendant Babel of classifi- 

 cation has not really fused and confused the four vertebrate 



