Fauna von Süd-Afrika. 565 



mucli tlie sanie conditioii as tliose I fouud still submerged a month 

 later, was takeii in October in a disnsed quarry. It was surrounded 

 by a mass of S. carteri three inches in diameter, and was attaclied 

 to a lierbaceous annual. The point on tlie edg'e of tlie quarry at 

 whicli tliis plant grew was not reaclied by the water until July. 

 It is tlierefore necessary to assunie tliat the genimules of S. hom- 

 hayensis had been formed between July and October. Probably the 

 larva of the spong-e had settled down on the i)lant during the 

 "rains" — which commence in Bomba}- about tlie beginning of 

 June — and had grown rapidly. The production of gemmules 

 may have been bi'ought about owing to the sponge being choked 

 by the more vigorous growth of S. carteri ^), a species which grows 

 to a considerable size in a comparatively short time, while S. honi- 

 haijcnsis apparently never reaches a thickness of niore tlian a few 

 millimetres. 



In India the season of greatest vegetative activity in most 

 freshwater sponges is the cold weather. S. carteri, the conimonest 

 species, as a rule dies down in spring, after producing both gonads 

 and gemmules. The larvae settle and in some cases grow to a 

 considerable size during the hot weather and the succeeding "rains". 

 A very large proportion. however, appear to perish. The gemmules 

 remain quiescent until the temperature sinks in October or November, 

 and then sprout. It is rare to find gemmules in growing sponges 

 of this species during the period between March and October. In 

 September and October eggs are often produced. Gemmules are 

 produced at all seasons by sponges actually undergoing desiccation, 

 which occurs most commonly in December, January and February; 

 in those sponges which remained submerged, gemmules as a rule 

 commence to develop in February or ]\rarch. Many otlier freshwater 

 sponges (e. g., S. alba, S. crassissima and Ephydatia ■meyeni] have a 

 similar annual history in the Calcutta "'tanks" or pouds, but some 

 small species (e. g., S. proliferens), the life of the individual sponge 

 of whicli is very short, continue to produce gemmules throughout 

 the year and apparently do not develop gonads, while others (e. g., 

 TrocliospowjiUa latouchiana) as a rule are found only during the 

 "rains", apparently because they frequent positions near the surface 



1) The largest speciraen I have seen forms an irregulär mass 30 cm 

 long, 26 cm broad and about 28 cm deep ; but this is perhaps the com- 

 bined growth of several years. 



