May 1, 1895. 



KNOWLEDGE 



97 



AN ILLUSTRATED 



MAGAZINE OF SCIENCE 



SIMPLY WORDED-EXACTLY DESCRIBED 



LONDON: MAY 1, 1893. 



CONTENTS. 



Some Strange Nursing Habits. Bv K. Ltdekkee, 



B. A. Cantab, F.R.S. (Illustrated) 



The Piace of Iron in Nature. By John T. Kemp. 



M. A. Cantab. 

 Breath-Figures. By Dr. J. G-. McPhebsox, F.E.S.E. 

 On the Two Forms of Primrose. By the Eer. Alex. ?. 



Wilson, JI A , B.Sc. (Illustrated) 



Baron Von Toll's Expedition to the New Siberian 



Islands. By Cael Siewees. (Illustrated) 

 Notes on a Solar Photograph. By E. Waltee Maundeb, 



FR.A.S. {Illustrated) 



Another Spectroscopic Binary Star. By Miss A. M. 



Clebke. (Illustrated) 



Letter :— A. E. Whitejiouse 



The Winter Life of Insects -II. By E. A. Butlee, B.A., 



B..'-'c. (Illustrated) 



Notices of Bool<s 



The Baltic Stream. By Richabd Betnon... 



Some Recent Patents. (Illustrated) 



The Face of the Sl<y for May. By Hebbeei 



Sadler, F.R.A.S 



Chess Column. By 0. D. Lococe, B.A.Oxon 



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118 

 119 



SOME STRANGE NURSING HABITS. 

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



WHILE the instinct of taking care of their 

 progeny, -whether these are born m the living 

 state or first come into the world in the form 

 of eggs, is more or less deeply implanted in 

 the higher vertebrates, among the lower 

 members of that great group the eggs and young are very 

 frequently left to shift for themselves. Still this state of 

 thmgs is by no means universally the case ; and we shall 

 show in the course of the present article that certain 

 amphibians and fishes exhibit structural modifications, for 

 the purpose of protecting their eggs and young, which are 

 almost or quite unparalleled elsewhere. Celebrated as 

 they mostly are on account of their highly developed 

 parental instincts, birds exhibit no instances where the 

 body of either parent is specially modified for the purpose 

 of carrying about either the young or the eggs after their 

 extrusion. And we believe that the same holds good with 

 regard to reptJes, although into the disputed question 

 whether vipers afford protection tj their young by allowing 

 them to run down their throats we are not going to enter 



here, beyond confessing that we are inclined to trust 

 the numerous observers who state that they have seen the 

 phenomenon with their own eyes. With a certain group 

 of mammals — the marsupials — the case is, however, very 

 different, many of them, like the Icangaroos, carrying their 

 imperfectly developed young in a special pouch borne on 

 the body of the female until sufficiently advanced to take 

 care of themselves. lu the females of certain other 

 members of the same order, namely, some of the American 

 opossums, the young are carried on the parental back, with 

 their own tails tightly twisted round that of their mother ; 

 while bats carry their helpless offspring tigbtly clinging to 

 their breasts, and the females of many lemurs bear them 

 clinging transversely across the under surface of the lower 

 part of their bodies. Now we shall ficd that among 

 amphibians there are several instances where the eggs or 

 young are carried about, either attached to the skin or 

 borne in special receptacles ; and as he knows that the 

 relationship between mammals and ampLibians is much 

 closer than any which exists between the former and either 

 birds or reptiles, the thoughtful naturalist cannot help 

 being struck with this similarity as regards their nursing 

 arrangements. Although not for one moment do we 

 suggest that there has been any sort of inheritance in this 

 matter, yet the coincidence is none the less striking. 



Commencing with that group of amphibians represented 

 by the frogs and toads, we find among these numerous 

 instances of abnormal ways of protecting their young 

 during the early stages of development, one of which has 

 been known for nearly a couple of centuries, while many 

 of the others have but recently been described. So far 

 back as the year 1705, Fiiiulein Sibylla von Merian, in a 

 work on the reptiles of Surinam, described a remarkable 

 toad-like creature, in which the young are carried in a 

 series of cells in the thick skin of the back of the female, 

 which at this period has a honeycomb-like appearance. 

 Till last year, when living examples were received by the 

 London Zoological Society, the Surinam toad (Pipa 

 americana), as the animal in question is called, was, we 

 believe, only known in Europe by means of specimens pre- 

 served in spirit ; and we have, therefore, been obliged to 

 depend upon foreign observers for an account of its 

 marvellous life-history. As it differs from other members 

 of its order with regard to its method of bringing up its 

 family, so the Surinam toad is structurally more or less 

 unlike all its kindred, constituting not only a genus but 

 likewise a family group by itself. Externally it is charac- 

 terized by its short and triangular head, which is furnished 

 with a large flap of skin at each corner of the mouth, and 

 has very minute eyes. The tour front toes are quite free, 

 and terminate in expanded star-like tips ; but a large web 

 unites the whole five toes of the hind foot. In any state 

 the creature is by no means a beauty, but when the female 

 is carrying her nursery about with her she is absolutely 

 repulsive in appearance. It would seem that soon after 

 the eggs are laid, they are taken up by the male and 

 pressed, one by one, into the cells in the thickened skin of 

 his partner's back ; there they grow till they fit closely to 

 the hexagonal form of their prisons, each of which is closed 

 above by a kind of trapdoor. After a period of some eighty- 

 two days, the eggs reach their lull development and 

 produce, not tadpoles, but actually perfect little toads. 

 The reason of this is that tadpoles, which require to 

 breathe the air dissolved in water by means of their 

 external gills, could not exist in the cells, and, couse- 

 quenily, this stage of the development is passed through 

 very rapidly within the egg. When ready to come lortti, 

 the young toads, which are usually from sixty to seventy 

 in number, although there may sometimes be over a 



