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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



SNAKE-INCUBATIOK 



THE Zoological Gardens of London, always 

 attractive, now and then acquire even ad- 

 ditional interest by the arrival of some new in- 

 mate, or the occurrence of some rare event among 

 those already established there. Last year the 

 Prince of Wales's Indian collection of animals, 

 the year before the snake-eating snake, drew ex- 

 tra crowds ; and of late the anaconda from Brazil 

 has rendered herself popular by bringing forth a 

 family of snakelings; though, owing to the ef- 

 fects of her long journey and close imprisonment, 

 her young ones were dead. A few years ago the 

 largest snake in the gardens was an African 

 python, that deposited above one hundred eggs 

 in a nest of moss which had been supplied to 

 her; and as some writers about snakes had told 

 us that the python incubates her eggs, and that 

 only this kind exhibits any such maternal in- 

 stinct, she also drew crowds of the curious. 



The pythoness whose proceedings we are 

 about to relate, having deposited her eggs, ar- 

 ranged them in a level mass and then coiled her- 

 self around and over them ; sometimes they could 

 be just discovered between her coils, and some- 

 times she covered them entirely. Heat combined 

 with moisture is essential to the development 

 of snakes' eggs ; and, in the choice of a spot in 

 which to deposit them, the maternal instinct of 

 the animal in a state of freedom is evident. It is 

 generally among decaying vegetation where heat 

 is generated, or in some moist, soft herbage where 

 the sun's rays can penetrate. To regulate the 

 temperature in a close cage and keep the moss 

 precisely in a condition to suit snake require- 

 ments was by no means easy, and our pythoness 

 seemed far from satisfied. The fact, however, 

 was established beyond doubt that she was hatch- 

 ing her eggs by the warmth of her own body. 



But a most untoward disaster happened one 

 night in the overflowing of the tank among her 

 eggs, completely saturating them ; and it was not 

 surprising, therefore, that no young pythons ap- 

 peared. The enormous reptile remained coiled 

 around and over her addled eggs for above seven 

 weeks, after which they were taken from her. 

 She had, and with good reason, been exceedingly 

 irritable and even savage during this time of 

 trial, as it was mid-winter, the season when under 

 other circumstances she, like her companions, 

 would have been half torpid. But her mater- 

 nal affection was undeniable, and this alone was 



worth witnessing ; since some authors would have 

 had us believe that snakes (and particularly non- 

 venomous ones) manifest entire indifference re- 

 garding their eggs and young. The python's eggs 

 being, as usual, in one long string, the keeper 

 had no little trouble in getting them from under 

 her. 



Being aquatic in their habits, and on that ac- 

 count requiring much water, anacondas are diffi- 

 cult to keep in captivity. The one lately arrived 

 among us was no sooner released from its travel- 

 ing-box than it took to the tank with which its 

 cage is furnished, and remained in it for hours 

 and even days together. But not there, poor 

 thing, can its swimming powers be displayed, 

 since in close coils it completely fills it. Not- 

 withstanding these drawbacks of London life, the 

 Gardens can now boast of three of these valuable 

 snakes, one of which has been a resident since 

 1869 ; while those in Paris have not survived any 

 length of time. 



One still more remarkable characteristic of 

 the anaconda is that, like the sea-snakes {Hydro- 

 phidce), but unlike the python, it produces its 

 young alive. We have long been accustomed to 

 think that only vipers produce live young — and 

 hence their name — and that all the non-ven- 

 omous snakes lay eggs. But snakes, so far as 

 those in captivity are concerned, are continually 

 doing what is not expected of them. Zoological 

 Gardens afford valuable opportunities to students 

 for acquiring knowledge of the form, size, habits, 

 etc., of animals, and an occasional insight into 

 their modes of life unattainable otherwise. This 

 is especially the case regarding the Ophidians ; 

 creatures which in their native haunts are so re- 

 tiring, inaccessible, and mostly nocturnal, that 

 less has been known of them than of almost any 

 other^ tribe of creatures. Regarding the subject 

 in question, several very important zoological 

 facts have recently been established at the Gar- 

 dens, and we may add, to the surprise of the 

 naturalist world in England. In 1862 (the same 

 year in which the pythoness laid her hundred 

 eggs), the then but slightly known non-venomous 

 English snake Coronclla Icevis gave birth to a 

 family of six live young ones in a cage in Lon- 

 don ; and several other harmless snakes in the 

 London ophidarium have also afforded cause for 

 surprise, not only in producing live young, but in 

 manifesting a very decided care for them. Some 



