406 
c and d). The plant has only a few rhizoids (fig. 67, e). The main 
branches are about 60 ^ thick. 
Forma varians is marked by being subject to considerable 
variation in the form of its sporangia, and even if the Fseroese 
Fig. 68. Ectocarpus siliculosus (Dillw.) Lyngb. f. varians Kuck. Different parts of the plant. 
a, b 100 : 1; c, d, e, f 150 : 1; g 270 : 1. 
specimens do not exhibit the extreme variations described by 
Kuckuck, 1. c., yet I feel quite justified in referring the specimens 
found by me to this form, and Dr. Kuckuck to whom I showed 
my preparations agrees with me in this. Fig. 68 represents some 
fragments of this plant. As may be seen, the form of the sporangia 
varies considerably, being sometimes like typical siliculosus , some- 
