Notes on Some South African Tadpoles 61 



void of the swimming tadpole stage. Its eggs will be found, I 

 think, hidden deep in the ground, perhaps in a termite mound. We 

 know, at any rate, that in other parts of the world a few frogs 

 and toads have abbreviated their life histories to the extent of 

 completely omitting the tadpole stage, but until recent years no 

 such case has been brought to light in Africa. The Jan Blom 

 resembles the species above-mentioned in possessing eggs dis- 

 tinctly larger than those of an ordinary frog and, moreover, 

 comparatively few. In an adult female example from Grahams- 

 town I counted only about 30 eggs excluding very minute ones, 

 whereas those of most frogs and toads number many thousands. 

 The thousands of small eggs that successfully serve the main- 

 tenance of a race in a normal environment may be less likely 

 to survive the perils of a waterless country than a few large ones 

 that rapidly transform into active little frogs. 



Nevertheless, the omission of the tadpole stage is not a usual 

 phenomenon amongst the frogs and toads that inhabit the arid 

 districts of South Africa. The several species that occur common- 

 ly in the Karroo (Rana and Bufo) certainly pass through a 

 tadpole stage. However, the metamorphosis of an average karroo 

 species, although probably just as complete as that of any other 

 frog, seems to be passed more rapidly than is the case amongst 

 its relatives in better water regions. According to Mr. J. H. 

 Power, the little toad Bufo veriebralis, that breeds in muddy 

 pools near Kimberley and Victoria West, passes through the 

 whole of its metamorphosis, from the laying of the eggs to the 

 time when the young toad jumps out into the world in sixteen 

 days. These are no statistics relating to the metamorphosis of 

 -other species of Bufo in S. Africa, but it is of interest to note 

 that the corresponding figures for the European species are 8-12 

 weeks for Bufo vulgaris, 2 months for B. viridis and 5-8 weeks 

 for the natterjack, B. calamiia. 



A few years ago. Dr. Geo. Rattray discovered a remarkable 

 instance of simpHfied life history in a frog that lives on the 

 Amatola range near Hogsback. This little creature has the 

 habit of laying its eggs in a small chamber just beneath the surface 



