90 



larvae hatched from one egg batch on 11th June measured respec- 

 tively, five weeks later, 4 mm. and 15 mm. Owing to their telescopic 

 nature it was exceeding difficult to measure them accurately, so 

 these figures must be taken as merely approximate. 



" They did not appear to be cannibalistic in their habits, as several 

 of various sizes were reared in the same dish and sometimes kept 

 short of food, but were never seen to attack each other. When one 

 died, however, its comrades usually devoured it. 



" When not feeding they spent most of their time buried in the 

 sand, with just the tips of their respiratory syphons showing. If 

 the sand was allowed to dry they became very restless, and would 

 make continual efforts to escape from their jars until water was given 

 them again. 



" Early in August, when they were about eight weeks old, they 

 ceased feeding, and were then transferred to jars containing sand to 

 a depth of 6 cm. They descended to the bottom of these jars, 

 and were still there when, some six weeks later, I went to England 

 on leave. 



" I returned to Khartoum on 28th January, and the jars then 

 contained several dead adults — all males — a few dead pupae and 

 larvae, and a single live larva. This last perished early in February 

 without having reached the pupal stage. The empty pupal cases 

 were all sticking up out of the sand, the pupse having evidently 

 worked their way up from the bottom of the jars by means of their 

 abdominal spines. In several cases the old larval skin had remained 

 attached to the caudal teeth of the pupal case. 



" The eggs from which these seroots were bred were obtained in 

 the marshes in the vicinity of Taufikia." 



