January 1, 1895.] 



KNOWLEDGE. 



3 



" natural " diet may be — ducks, frogs, rats, mice, pigeons, 

 lizards, guinea-pigs, rabbits, other snakes, small birds, or 

 what not. And I have proved to demonstration that they 

 thrive better, keep more healthy, and become tamer, when 

 submitted to this process, than do any which are willing to 

 depend upon their own exertions for their subsistence. A 

 moiety of the individuals of the same broods, as well as 

 fresh arrivals selected at random from a group of the 

 same size, weight, and condition, have been so treated by 

 me to the number of some hundreds, and in almost every 

 case have grown bigger than those which fed voluntarily, 

 while, even setting aside starvation, my losses by death are 

 almost "(7. The other day I sent to the Zoological Society's 

 Gardens a diamond snake of a size never seen there 

 previously, reared in this way ; and I am able to keep alive 

 and in grand condition delicate species like some of the 

 tree-boas, shy feeders such as the smooth ' snake and 

 viper, and those whose food in ordinary — consisting of 

 lizards or their own kind — would be well-nigh impossible 

 to procure in sufficient quantity, like the coral snakes of 

 tropical America. Furthermore, I have at the present 

 moment a Trinidad boa which broke its jaw some years 

 ago, and a West African python with a stricture of the 

 (Psophagus, the result of injury received in capture, both of 

 which are fat and happy, though quite incapable of feeding 

 themselves. 



Pure tlesh I soon found to be too stimulating for them, 

 causing them to shed their skins too frequently ; so, when 

 I have them, I add some dead frogs or common mice. In 

 default of these, a handful of feathers or cinders, or pieces 

 of soft string wrapped round the lumps of meat, do just as 

 well, supplying the place of the bones, fur, or feathers of a 

 swallowed animal as a mechanical aid to the digestive 

 function. Newly-hatched specimens, which I used to treat 

 with raw beef tea, mixed for digestive reasons with arrow- 

 root or curdled milk, I now cram with meat in precisely 

 the same way. I should say here that every snake will 

 drink of its own accord, so that it is not necessary to 

 administer water artificially. A boa or python ten feet 

 long gets three pounds of beef or horseflesh about once a 

 month on an average, and other snakes more or less 

 according to their size ; though there can be no absolute 

 rule with regard to this, not even in the case of the same 

 individual. A minor advantage of this plan lies in the fact 

 that there is little or no fajcal excrement, the meat being 

 wholly susceptible of conversion and absorption. The 

 cages, therefore, require cleaning much less often, while 

 the pure sohd uric acid, which is excreted in large quantities 

 by the kidneys, is saleable for laboratory purposes to the 

 manufacturing chemists at a price varying with the market 

 from five to ten shillings per pound. Serpents appear to 

 have very little power of assimilating fat — some kinds less 

 than others ; if this be given in any quantity, it is simply 

 poured oft' by the intestine, mixed with bile. 



Cramming, though infinitely more convenient than the 

 maintenance of an unlimited number of live birds, beasts, 

 and reptiles to serve as food, has its little difficulties. 

 The subject of this delicate attention positively refuses 

 any connivance therewith under all circumstances, even 

 though it be starving to death, and manifests the 

 most determined opposition throughout — and four or 

 five yards of demonstrative disfavour is no mean factor 

 of antagonism in any mundane concern. The first 

 thing is to get a good grip of the neck, just behind the head, 

 with a degree of firmness whicli will do no injury and yet 

 prevent escape, a grip only to be acquired by habitude. 

 (It is extraordinary how one gains a sort of tactile instinct 

 in dealing with these creatures, a kind of muscular sense 

 which tells one what they are going to do.) For small 



ones, a bag may be recommended to restrain the move- 

 ments of the body ; but with the larger constrictors, pythons, 

 and anacondas there is nothing for it but a rough and 

 tumble struggle on the floor, and the use of bare hands, 

 the legs, and stockinged feet. With a silver spatula I open 

 the jaws by firm but gentle pressure in front, always 

 taking advantage of the position to examine the mouth for 

 the earliest signs of " canker." The interior should be 

 dry and white ; at the outset of canker the mucous mem- 

 brane is swollen and has the appearance of red velvet, 

 bleeding on the slightest touch, and flecked here and there 

 with white aphthous spots. Then my assistant thrusts a 

 piece of meat between the triple rows of teeth, and with 

 the hand at liberty I push it down fairly into the stomach, 

 using for the purpose a flexible india-rubber rod, but 

 relying chiefly on pressure above the lump on the gullet 

 outside. Very often we are compelled to hold on with all 

 our might for a considerable time to prevent its return ; but 

 we are generally successful, and I think I may say that we 

 do not experience the disaster of regurgitation once in five 

 hundred crammings now — we were not so lucky at first, 

 but have learned a good deal since then. And it is my 

 earnest conviction that if this process were adopted in 

 Zoological Gardens and other menageries, it would not 

 only prevent the dreadful waste of ophidian life which 

 goes on at present, but would result in an enormous 

 economy of time and money, and might, moreover, admit of 

 the solution of sundry physiological problems of the 

 deepest interest. 



SPOTS AND STRIPES IN MAMMALS. 



By E. Lydekkeh, B.A.Cantab., F.R.S. 



THOSE of our readers who have considered the 

 subject at all are probably aware that, in those 

 animals whose fur is ornamented with dark or 

 light markings, these markings generally take the 

 form either of longitudinal or transverse bands, or 

 of spots ; the latter being frequently arranged in more or 

 less distinctly defined longitudinal lines, but never in 

 transverse bands. Moreover, these markings, especially 

 in the case of stripes and bands, are generally most 

 developed on the upper surface of the body, although spots 

 may be equally present on both the upper and the lower 

 surfaces of the body. Many mammals, again, whether 

 they be spotted or whether they be striped, have their 

 tails marked by dark rings on a light ground ; but this 

 feature is also present in others in which the colour of the 

 body is of a uniform tint. It must not, however, be 

 supposed that there is any sharply-defined distinction 

 between spotted and striped mammals, many of the civets, 

 as well as some of the cats, having markings intermediate 

 between true spots and stripes. Spots, again, are some- 

 what variable in configuration, some animals, like the 

 hunting-leopard, having solid circular dark spots, while in 

 others, such as the leopard and jaguar, they assume the 

 form of dark rings enclosing a light centre. In other 

 cases, as in the girafle, the spots are enlarged so as to 

 form large and more or less quadrangular blotches. 



A survey of a museum or a menagerie will likewise 

 show that spots and stripes are by no means equally 

 prevalent in all groups of mammals. In the apes, monkeys, 

 marmosets, and lemurs, for instance, they never occur ; 

 and when these animals are diversely coloured, the colora- 

 tion takes the form of patches symmetrically disposed on 

 the two sides of the body, but otherwise not following any 

 very clearly defined mode of arrangement. Then, again, 

 in the hoofed mammals, or ungulates, many species are 



