594 Annals of the South African Museum. 



During the development of the sperm globoid the vesicle formed from 

 the wall of the mother-cell enlarges greatly, allowing ample room for 

 the movement of the globoid within it. Not only does it remain 

 intact throughout development, but even after the globoid has 

 escaped the vesicle can be seen unbroken, except at the pore of 

 escape. In fairly old male colonies such empty vesicles often show 

 clearly among developing sperm globoids. 



Time taken for Inversion. It is very difficult to determine exactly 

 when the preparatory stage begins, but it is clear that it is prolonged. 

 There is apparently considerable variation in the time taken over 

 inversion. For instance, in one case a male bundle came under 

 observation when the lip was already rising. In 14 minutes it had 

 straightened out and in another 80 minutes had completely inverted 

 and started moving. This was unusually quick. 



In another (Series X, shown in Plate XLIII, figs. A to K) when 

 first observed the lip was already depressed but did not reach maximum 

 depression for another 35 minutes. During the next 75 minutes it 

 was slowly rising, finally straightening out. The opening of the pore 

 to its widest extent (Thimble) took 1 hour 55 minutes, the actual 

 inversion took another 1 hour 48 minutes total, 5 hours 33 minutes. 



After inversion is complete the final depressed form may be attained 

 in from 45 minutes to an hour, or longer. 



In several cases a given male bundle was under observation for over 

 6 hours, by the end of which time the globoid had started moving. 

 To this time, however, must be added an unknown, probably varying, 

 time for preparation before the bundle came under observation. 



As a general rule, the process is very slow up to the " Thimble ' ; 

 stage ; but once the pore has reached its maximum size, which corre- 

 sponds with the minimum size of the bundle as a whole, and the lip 

 has started to curl outward, the rate rises and the actual process of 

 inversion takes place comparatively rapidly. In general the period 

 of preparation lasts for at least 2 to 3 hours, often more, while the 

 period of inversion proper takes another 1 to 3 hours, while after 

 inversion is complete another hour or more elapses before the globoid 

 has assumed its characteristic form. 



5. Escape of Sperm Globoid. 



After the globoid has reached the stage described above it remains 

 within the parent colony for some time, exactly how long has not been 

 determined. The movement which started as soon as inversion was 



