ESTIVATION OF BOTRYLLOIDES GASCOI DELLA VALLE. 



153 



Table I. 



Remarks. 



Received the colony and set it out in the bay. 



Put one piece in an aquarium. 



It is changing zooids. 



The old zooids have disappeared; the cloacal orifices of the young zooids have not 



yet opened. 

 Yellow lobe formed, zooids have degenerated. 

 Condition of June 29 retained. 

 Lilac part dead and disintegrating. 

 Buds have appeared in the translucent part of the yellow lobe. Two have their 



siphons open. (Half of colony fixed and sectioned.) 

 All the buds have greatly degenerated. 



New small buds are bunched together on the edge of the colony. 

 Separated into two groups. 

 The buds have again degenerated. 

 The new buds are of medium size, siphons closed; they have appeared in the same 



place. 

 Bunched on edge, no systems, no siphons open. 

 Three new buds in a separate lot. No siphons open (Fig. 1). 

 The new buds have degenerated, and the ten large ones have .formed a system. 



Siphons open (Fig. 2) . 

 Zooids of July 30 have degenerated, new zooids have appeared on a different part 



of colony and have formed two systems. 

 One system has degenerated, the other persists (Fig. 3) . 

 Siphons open. Some zooids degenerating rapidly (Figs. 4, 5). 

 Only one zooid remains, but many small buds have appeared (Fig. 6). 

 The old zooid still persists; 13 buds (Fig. 7). 



The old zooid still persists; the tip has grown 1.4 mm. since Aug. 18 (Fig. 8). 

 One system formed, siphons open. The tip has grown 1.6 mm. since Aug. 19. Two 



buds that were left behind are degenerating (Fig. 9) . 

 The opaque part has died; the colony has completely recovered. 

 Two systems. 

 Changing zooids. 

 New systems established. 

 Changing zooids; the 115 zooids are all young. 

 New systems formed. 

 One end of the colony is changing zooids. 

 Change completed. 

 Two systems formed. 

 Has changed zooids; these are one or two days old. 



did not grow, contained but few buds, and a translucent part which grew rapidly and 

 developed most of the buds. Accordingly it was found that the whole new colony 

 was developed from the transparent part, and that the opaque part died on Sep- 

 tember 10. 



This law of growth held not only for different parts of the colony, but also for the 

 individual buds and zooids. Not only did the buds usually arise in that part of the 

 colony that was growing most rapidly, but they grew along with it in its wanderings 

 over the substratum. This growth or wandering was not always in a centrifugal 

 direction. At one time, the growing part apparently experienced too much resistance 

 in growing over the glass and turned back accompanied by its buds and zooids, and 

 progressed over the inert opaque part of the colony (Figs. 7, 8, 9). This progression 

 of the buds and zooids seemed in great measure to be an active process on their part, 



