870 Scientific Intelligence— Zoology. 



mical Department of the Museum of the Royal College qf Sur- 

 geons in Ireland. — In Dr Houston"'s excellent catalogue there 

 are numerous interesting details regarding the anatomical and 

 physiological relations of animals well deserving the attention of 

 naturalists. Of the different portions of the collection, as re- 

 marked in the Dublin Medical Journal, that devoted to the 

 anatomy of the circulating system seems most complete, consist- 

 ing of nearly 300 specimens. We shall make our extracts from 

 this portion of the Catalogue. Here we meet with one of those 

 wonderful contrivances — those adaptations of means to end — 

 with which comparative anatomy abounds ; and as this subject 

 seems to have been a favourite with our author, we shall follow 

 him out in his researches. The existence of a double heart, 

 warm blood, and an active inervation, implies a corresponding 

 respiration, which cannot be interrupted for any length of time 

 without producing death by asphyxia. But we find among the 

 vertebrated and warm-blooded animals a class in which the tem- 

 porary suspension of respiration is a necessary result of their mode 

 of life, as we see to occur in the whole tribe of warm-blooded 

 diving animals. ,Thus, the whale, the seal, the porpoise, the 

 otter, and also diving birds present examples [of this. Here, 

 so long as the animal remains under water, the mechanical, che- 

 mical, and vital acts of respiration are suspended, and were it 

 not prevented by some special provision, the accumulation of 

 blood in the venous system must be injurious. In order, how- . 

 ever, to obviate such accident?, a beautiful provision is adopted, 

 consisting, first in the existence, of what may be called a supple- 

 mentary or additional venous apparatus; second, in the increase 

 of volume of certain of the internal trunks ; and, thirdly, in the 

 formation of vast reservoirs communicating with the venous sys- 

 tem, and which receive the blood during the stoppage of respi- 

 ration. The discovery of this curious apparatus is not new to 

 comparative anatomists ; but our author has the credit of first 

 demonstrating its existence in many animals, and also in shew- 

 ing that the amount or extent of the apparatus was proportioned 

 to the length of time the animal usually remains under water. 

 We shall insert some of his descriptions: — " B. c. 379. A dried 

 injection of the heart and bloodvessels of a seal ( Phoca vitu- 

 JmaJ^the arteries red, the veins yellow. There is nothing very 



