THE AQUAEIUM, JULY, 1895. 



181 



twenty to forty illustrations ; a great 

 many specimens of soils, dredgings and 

 minerals from all parts of the globe. 

 This entire collection, together with the 

 microscope Ehrenberg had in constant 

 and exclusive use since 1832, was bought 

 by the Prussian Government and deliv- 

 ered personally by Ehrenberg in May, 

 1876, June 27, 1876, he died and was 

 buried at Berlin. His grave is marked 

 by a plain obelisk that shows in front 

 his bust in bass-relief, and in the rear 

 the motto which he had selected in 

 connection with his doctor essay : 



Der Welteu Kleiues auch ist wuuderbar 



unci gross, 

 Und aus dem Kleiueu bauen sich 



die Welten. 



A COLONY OF YOUNG FEOGS 

 ON THE PARENTAL BACK. 



The remarkable habits of some tropi- 

 cal frogs that nurse their young, as it 

 were, by carrying them about on their 

 backs, are described in Knowledge (May 

 1), by Mr. R. Lydekker, in an article 

 from which we quote below : 



" So far back as the year 1705, Fraeu- 

 lein Sibylla von Merian, in a work on 

 the reptiles of Surinam, described a re- 

 markable 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 

 3'ear, when living examples were re- 

 ceived by the London Zoological So- 

 ciety, the Surinam toad {Fipa Ameri- 

 cana), 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, there- 

 fore, been obliged to depend upon for- 

 eign observers for an account of its 

 marvelous 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 characterized 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 four 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 appear- 

 ance. 



"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 part- 

 ner'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 trap-door. After a 

 period of some eighty- two days, the 

 eggs reach their full development and 

 produce, not tadpoles, but actually 

 perfect little toads. The reason of 

 this is that tadpoles, which require to 

 breath the air dissolved in water by 

 means of their external gills, could not 

 exist in the cells, and, consequently, 

 this stage of the development is passed 

 through very rapidly within the egg. 

 When ready to come forth, tne young 

 toads, which are usually from sixty to 

 seventy in number, although there may 

 sometimes be over a hundred, burst open 

 the lids of their cells, and, after stretch- 

 ing forth their head or a limb, make their 

 di'but in the world. Doubtless, glad to 

 be free from her charge, the mother- 

 toad thereupon rubs off what remains 

 of the cells against any convenient 



