12t 



vipai'ous. Scientists make a distinction between those animals beat- 

 ing living young which represent the laying of an egg that hatches 

 at the time it is laid, and those bearing young which have been 

 nourished by direct connection with the circulatory system of the 

 parent. An animal with the former method of reproducing the 

 young is called ovoviviparous. In this the embryo or undeveloped 

 young is nourished by a yolk within the thin membrane, and this 

 embryo remains and develops until the yolk is all absorbed, when 

 it is practically hatched and born at the same time. There is no 

 vital nourishing connection as in the case of the viviparous animal, 

 such as the mammals or hairy quadrupeds. With this explanation 

 we can say that snakes are oviparous or ovoviviparous, and are not 

 to be called viviparous, although bearing living young. In this 

 State no reptile produces more than one brood of young per year. 

 The oviparous or egg-laying species, as a rule, produce many more 

 offspring in a brood than do the ovoviviparous species of the same 

 size. One reason for this is that with the latter the young are much 

 larger than the eggs would be, and occupy a great deal more space. 

 Thus, in making provision for the increased size of the undeveloped 

 young, the only thing that nature can do is to reduce the number. 



The relationship, which we believe only general, but of which we 

 have seen no published statement, is that most of the oviparous or 

 egg-laying species of serpents belong to the constricting group, 

 which kill ther prey by squeezing it; while most of the ovovivi- 

 parous serpents are species which take their prey with their mouths, 

 and do not kill by constricting. The explanation for this may be 

 that if the serpents of the latter group should exert pressure suffi- 

 cient to kill their victims it would also crush the embryos or unde- 

 veloped snakes, ^^hi(•h are protected only by a thin membrane. Thus 

 the constrictors, like the lilack Snakes, lay eggs that are covered 

 with thick ])rotecting mcnibi-anes, which are soon laid, and the em- 

 bryos of which are not injured by the pressure which is often needed 

 for the parents to kill their pre}'. 



Remedies for Snake Bites. 



Remedies for snake bites are of considerable importance, as it must 

 be remembered that two venomous snakes, the Copperhead and the 

 Rattler, are abundant in certain parts of this State, and even during 

 this sumuKT there have been reports of human beings dying from 

 the bites of rattlers as well as copperheads within the Common- 

 wealth of Pennsylvania. We have verified these reports by corres- 

 pondence and must recognize their accuracy. 



When a person is bitten by a venomous snake the first thing to do 

 is to place a ligature as tightly as possible between the wound 



