CONGDON. — THE HYDROIDS OF BERMUDA. 



469 



(Figure 11). The outgrowths arise from the ends of the stems and 

 branches or may replace the latter. They are present in colonies of 

 all sizes and are most abundant at the distal end. By their elongation, 

 sometimes aided by a bending of the colony, their tips come in contact 

 with the substratum. A clump of rhizoids forms and a new colony 

 rises from them. Only a small proportion of the stolons were engaged 

 in this process. Hincks ('68, p. 170) figures similar stolons on C, 

 aiKjuUdn, but they were not seen to give rise to colonies. 



Nutting (:00, p. 44) has seen a species of Aglaophenia in the act of 

 conjugating by means of stolons. A hooked stolon of one colony 

 catches a similar structure of another. Fusion occurs, and after a 

 resting period of three months a colony arises at the point of contact. 



Figure 10. Campanularia insignls. Branch and part of main stem, showing 

 two t\'pcs of gonophores (X 4). 



Though I found no case of fusion in many hundred colonies, the possi- 

 bility of its occurrence is suggested by the hooked ends of the young 

 stolons. Sometimes a small hooked stolon arises perpendicularly from 

 near the end of another. As the branches grow larger, the hook 

 gradually straightens, until there is but a slight curve, as found in 

 C. angulata, S. piimila, and other species. 



Gonosome. I found two types of gonothecae. The one was cylin- 

 drical and divided into about five lobes by regular and broad furrows 

 (Figures 10, 12). It was not apparent from their structure whether they 

 were female or immature male gonothecae, and I was not able to inves- 

 tigate their histology. The other form Avas ovoid with a constricted 

 opening and a single male gonophore (Figure 10). 



The spermatozoa develop in gonothecae instead of in medusae. A thick 

 layer of sperm mother-cells lies next the mesogloea in the entoderm. 



