ZOOLOGY. 331 



beavers came down, examining either bank carefully. One of the 

 party always remained in the water, and seemed to be the com- 

 mander, and would turn from the one to the other to see that each 

 did his duty. At length they reached the dam, still observing the 

 same caution. The three examiners came out and went all over it 

 and into the sluice, chattering the while to their companion in the 

 water. Finally, they seemed satisfied that it was past their skill, and 

 went off. Since then we have had no further trouble with them." 



THE WINTER SLEEP OF MARMOTS. 



The winter sleep of marmots has been investigated by M. G. Val- 

 entine, particularly with respect to the movements of the heart and 

 respiration, and the intravascular pressure during sleep. The inser- 

 tion of a needle into the apex of the ventricles was borne by a mar- 

 mot twenty-four hours without waking ; the sleep even appeared to 

 be more profound, and the number of pulsations increased. The dura- 

 tion of each pulsation is longer when the animal is asleep than when 

 it is awake. 



The shaking of the table on which it was placed, and the moist- 

 ening the sole of its foot with sulphuric acid, sensibly increased the 

 number of pulsations. With respect to the intravascular pressure, 

 M. Valentine states that the abstraction of a considerable quantity 

 of blood by secondary hemorrhage caused the marmot, after six hours' 

 sleep, to wake up to vigorous action. 



SHEDDING OF THE ANTLERS OF THE RED DEER. 



At a recent meeting of the Boston Society of Natural History, Pro- 

 fessor Wyman gave an account of some observations on the shedding 

 of the antlers of the American red deer. 



After the rutting season is past, and, in consequence of the stop- 

 page of the circulation through them, they have become dry and 

 dead, the antlers are separated from the living frontal bone by a 

 process of absorption carried on by the Haversian canals. These, 

 acting on one plane through the whole thickness of the bone just be- 

 low the " bur," remove the solid materials around them, so that each 

 canal becomes dilated on that plane until its cavity unites with that 

 of an adjoining one. When this process has extended entirely across 

 the base, the antler drops. The fall of the antler was shown to have 

 a close resemblance to the process by which, in necrosis, the dead is 

 separated from the living bone. 



He also was disposed to regard the antler as a dermal bone, rather 

 than a portion of the endo-skeleton ; 1st, because it is developed in 

 the integuments by a special centre of ossification, and only becomes 

 attached to the frontal bone after ossification has somewhat advanced ; 

 2d, because the permanent antlers of the giraffe do not become united 

 with the cranium, except by suture, until late in life, and are devel- 

 oped over the parietal as well as the frontal bones, without being di- 

 vided on the line of the sutures of these two bones, which they would 

 be were they merely epiphyses of them. 



