Among frogs and toads from distant lands are some which bring forth their young alive, the female retaining the eggs in her body instead of laying them in water. The black-and-yellow salamander of Europe (which, like the common toad, has a highly poisonous secretion in the skin) retains its eggs inside its body until the tadpoles are well advanced in development, when they pass from her—about seventy in number—into the water. In the closely allied black Alpine salamander only two, out of thirty or more eggs produced, develop. These two remain inside their mother until they have ceased to have gills and have become terrestrial air-breathing young salamanders like their mother. The Alpine salamander lives where there are no pools suitable for the tadpoles, and so they never enter the water, but remain inside the mother’s body. Some experiments have recently been made with these two species of salamander by varying the conditions as to moisture in which the young grow to maturity, and results of considerable interest have been obtained. One of the most curious arrangements in regard to the young is seen in the Surinam toad, of which we had living specimens five or six years ago in the London Zoological Gardens. In this toad the skin of the female’s back becomes very soft and plastic at the breeding-season. As she lays the eggs the male takes them one by one and presses them into the soft skin of her back, into which they sink. The eggs are thus embedded separately to the number of fifty or sixty, each in a little pit in the mother’s back. They slowly develop, each in its “pit,” the orifice of which is closed by a sort of lid. When the young have grown to the condition of little toads, they push open the lids of the pits and swim out of their mother’s back. Specimens of these toads, with the eggs and young, in various stages, embedded in their mother’s back, are to be seen in most museums of natural history. Toads and frogs catch their prey by throwing forward the sticky tongue which is attached near the front of the lower jaw, and so lick up their victim with startling abruptness. The Cape frog of South Africa (_Xenopus_), like the Surinam toad (_Pipa_), has no tongue, and is also remarkable for possessing hard, pointed ends to its toes. It rarely, if ever, leaves the water. FOOTNOTES [4] I am told by Mr. Boulenger, of the Natural History Museum, who is the greatest authority on these animals, that the explanation of this is that unawares Dr. Edwards made use of the young tadpoles of the obstetric toad (_Alytes_), which is very common near Paris, though it does not occur in England. These tadpoles regularly grow to be three inches and more in length (see Fig. 44 B). Dr. Edwards thought he had used the tadpoles of the common frog, but had, by accident, got hold of those of _Alytes_. XXIII ABOUT THE STARS