SSAT Middle Level: Reading Question of the Day

Adapted from “Some Strange Nurseries” by Grant Allen in A Book of Natural History (1902, ed. David Starr Jordan)

Among the larger lizards, a distinct difference may be observed between the American alligator and its near ally, the African crocodile. On the banks of the Mississippi, the alligator lays a hundred eggs or thereabouts, which she deposits in a nest near the water’s edge, and then covers them up with leaves and other decaying vegetable matter. The fermentation of these leaves produces heat and so does for the alligator’s eggs what sitting does for those of hens and other birds: the mother deputes her maternal functions, so to speak, to a festering heap of decomposing plant-refuse. Nevertheless, she loiters about all the time to see what happens, and when the eggs hatch out, she leads her little ones down to the river, and there makes alligators of them. This is a simple nursery arrangement of the big lizards.

The African crocodile, on the other hand, does something different, and takes greater care for the safety of its young. It lays only about thirty eggs, but these it buries in warm sand, and then lies on top of them at night, both to protect them from attack and to keep them warm during the cooler hours. In short, it sits upon them. When the young crocodiles within the eggs are ready to hatch, they utter an acute cry. The mother then digs down to the eggs, and lays them freely on the surface, so that the little reptiles may have space to work their way out unimpeded. This they do by biting at the shell with a specially developed tooth; at the end of two hours’ nibbling they are free, and are led down to the water by their affectionate parent. In these two cases we see the beginnings of the instinct of hatching, which in birds has become almost universal.

The author’s tone in this passage is primarily                     .