298 THE PHENOMENON OF 



horns, which, moreover, as in Vauch. sessilis, exhibit an 

 empty open end-cell at the period of maturation of the 

 spores. The genus Vaucheria, which has already so much 

 occupied naturalists, still requires, therefore, further and 

 more minute investigations in reference to the formation 

 of its reproductive organs. In conclusion, I will mention 

 certain other cases which bear some resemblance to the 

 phenomena of conjugation, and have been, in fact, really 

 regarded as such. In Saprolegnia, which exhibits so 

 much likeness to Vaucheria in morphological respects, 

 we find a structure similar to the horns of Vaucheria. 

 At the period of the formation of the resting-spores, 

 between the lateral branches swelling up into pear-shaped 

 spore-cases, appear frequently, but not constantly, slender 

 vermiform branchlets, which, when they reach the spore- 

 cases, apply themselves firmly upon these, and indeed 

 sometimes twine round them in irregular coils ; no actual 

 anastomosis takes place however. Coleochcete puhinata 

 (see page 161) exhibits a phenomenon which may be 

 compared with this. The sporangium of this species 

 originates by the expansion of the last or last but one 

 cell of a filament, and is, in itself, a simple cell, which, 

 however, acquires a most complete cellular envelope 

 through the close application upon it of cellular branch- 

 lets, partly arising from the cell immediately preceding it, 

 partly reach over like bridges from branches situated lower 

 down or neighbouring filaments. The direction, differing 

 from the ordinaiy erect growth, in which the branches 

 combining with the sporangium come in from all sides, 

 sometimes horizontally, and sometimes even descending, 

 shows, although there may not be so intimate a connec- 

 tion and so direct a co-operation for the formation of the 

 spore as in conjugation, that there is, nevertheless, here, 

 a similar reciprocity of attraction and seeking-out of the 

 parts, as well as a material assistance in the spore- 

 formation, through the connection of the mother-cell of the 

 spore with the numerous smaller cells forming the enve- 

 lope, doubtless effected through the process of endosmose. 



