sept. 1M9.] jHE OER3IINATI0N AND DEVELOPMENT. 173 



vase, as if a drop of yellowish dye. had been dissolved there. The 

 yellowish part of the water was pipetted out into two beakers 

 which were tilled beforehand with twice-filtered sea-water. 



The swarmspores liberated from the sori are strongly' 

 heliotaxic. They are ovate in general shape with the narrow 

 end more or less pointed, an^ measure about 7 i>. in length. A 

 cup-shaped chromoplast of uneven thickness fits in the blunt end, 

 holding a nucleus and a few fine granules within it. An e3'e- 

 spot is on a point in the colourless part near the margin of the 

 chromoplast, as an elongated elevation above the surface. Two 

 flagella arise from a small depression b}' the eye-spot, one 

 pointing forward and as long as about four times the length of 

 the body, and the other pointing backward and a little shorter 

 than the half of the former. The spores swim about activelj^ 

 in a zigzag manner, the body apparently rotating round the 

 longer flagellum as the axis (Fig. 2). 



Once I observed the swarmspores in December. They v^ere 

 elliptical-ovate in shape with the colourless end rounded ; the 

 eyespot was slightly nearer the posterior than the middle part 

 of the body, sitting, as it were, upon the chromoplast (Fig. 1). 

 Reinke^^ illustrates them as being oblong-ovate in shape with 

 acute narrow end, close bj' which the. two flagella arise. 



We are aware that there are frequently met with some 

 swarmspores, liberated from one and the same sorus, having 

 certain morphological differences from the others. Such differ- 

 ences as noted above may not be taken as a mere trifle and 

 meaningless. But I am not prepared at present to give any 

 explanation respecting this point. 



The plurilocular sporangia of the sori, or the trichc- 

 sporangia, of the Encoeliaceous members have been hitherto 

 regarded as gametangia. Positive evidence for this view has 

 been given by Kuckuck."^ Reinke's^^ observation proposes 

 a negative to this view. I paid special attention to this 



I) Keixke : 1. c. 



2j Kuckuck: Leber die Paarung von Schwiiriiisporen hei Sct/losiphou. Vorl. 

 Mitt; ^(Ber. der deutch. J5ol. Ges. ISHS. p. 35). 

 3) Eeinke: 1. c. 



