26 



If the water in the cultures is once quite clear, it only 

 wants adding to very occasionally. 



In tlie case of Chondrus crispus, I observed that the 

 tetraspore underwent division without at first growing very 

 much in bulk (fig. 27, 28). Then, however, after having 

 formed a small heap of cells, which are all very much 

 smaller than the original tetraspore, longish filaments 

 seem to be formed (fig. 29). These consist at first of 

 unbranched single rows of cells. Finally the commence- 

 ment of the formation of flat plates has been observed, and 

 in the end no doubt a normal flat attachment organ is 

 formed, from which the upright shoots arise. I have not 

 however been able to follow out the growth of the 

 germinating tetraspore to this stage yet. 



2. — The Spermophore. 



The spermatia or male cells are found on young portions 

 of the frond. The latter are temporarily modified only 

 for this purpose. Later on they evidently again take on 

 the functions and the structure, of an ordinary vegetative 

 shoot. They have been called spermophores (fig. -jO. 31). 



The spermophores of Chondrus crispus are small and 

 narrow, slightly flattened leaves. They appear white 

 owing to the fact that the rhodophistids of the assimilating 

 layers are but poorly developed. They are •'i-4mm. long 

 and barely Inim. broad. 



The general structure of the spermophore does not difi'er 

 from any ordinary young portion of the thallus. The 

 difference lies in the nature of the last few cells of the 

 assimilating filaments. The last two or three cells appear 

 to be colourless owing to the rhodoplastid, though present, 

 being very much reduced. These two or three cells 

 together form an antheridium, or male organ. The last 

 cell of the row, the spermatangium, gives rise to one 



