Howe : Phvcological studies 505 



water earlier in the day, our attention was arrested by one plant 

 of Avraitivillca uigricans, the surface of which was rather abun- 

 dantly covered with protruding capitate or subclavate filaments. 

 Remembering that " Fortpflanzungsorgane unbekannt " * was the 

 most that had been said of the mode of reproduction in this genus 

 Avrainvi/lca, which had been recognized since 1842, we proceeded 

 to examine the newly found structures with much interest. The 

 enlarged terminal portions of these filaments varied in form from 

 clavate and fusiform to pyriform or subglobose and they had the 

 appearance of being stipitate, being raised above the general sur- 

 face once or twice their own length by a scarcely modified part of 

 the filament. The younger and smaller as well as some of the 

 larger of these peculiar bodies were intensely green, contrasting 

 notably with the dingy-fuscous tint of the plant in general, but 

 many of the older and larger had turned brown, the color residing 

 partly in the filament wall and partly in the contents and being 

 evidently an intensification of the color characteristic of the ordi- 

 nary vegetative condition of the species. After a microscopic 

 examination, the plant was placed in a jar of seawater with the 

 hope that on the following morning living zoospores might be seen 

 to emerge from the suspected sporangia. But our hopes were 

 disappointed. Then, as on the previous evening, many of the 

 supposed sporangia contained usually from three to five (one to 

 eight) ovoid, pyriform, elongate-ellipsoidal, or difform bodies, 

 occupying together one-half or more of the cavity of the enlarge- 

 ment. Impressed by the evident lack of homology with what 

 little is known of reproduction in other members of the Codiaccac, 

 we suspected that these peculiar interior bodies might be endo- 

 phytic parasites of some sort and that the sporangium-like swell- 

 ings might be simply galls caused by their presence, and so, with 

 the conviction that the AvrainvilUa was by this time dead, we 

 added formalin to the seawater to preserve the interesting speci- 

 men for further study at some more convenient time. Subsequent 

 investigations have succeeded in bringing to light practically all 

 stages in the development of the sporangium-like organs, includ- 

 ing great numbers of withered and empty ones, and nothing has 

 been discovered to indicate that the more or less spore-like bodies 



* Wille ; Engler & Prantl, Nat. Pflanzenfam. i^ : 141. 1890. 



