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even smaller plants, I or 2 cms. in length were found on 
which the sori were completely merged into a uniform 
covering of sporangia, paraphyses and hairs, thereby 
approaching the condition described by Reinke for A. 
echinatus var. filiformis. The reduced forms of F. villosa 
are connected to the normal form F. tyfica by a series of 
intermediates. Professor Kylin suggests that the fluctua- 
ting stature and the associated morphological features of 
sorus-form and hairiness are correlated with variation 
in salt content of sea-water. This supposition rests on the 
fact that at the locality where F. ¢typica predominates to the 
exclusion of J’. villosa the sea-water reaches its maximum 
salinity for Swedish coasts and approximates to the 
condition of the sea-water on the Norwegian coast where 
F. typica is the normal form. 
The antithesis of a winter plurilocular and a summer 
unilocular sporangium producing thallus is not mentioned 
by Professor Kylin for his Swedish plants, but it is a 
noticeable feature of the Isle of Man plants. The 
segregation is however indicative of different physiological 
states of the plants and not attributable to inherent 
factors since both types of plant have been proved to be 
diploid in nuclear condition and moreover, in the spring, © 
both types of sporangia are found side by side on the same 
thallus. The facts of the case are that the small winter 
plants produce plurilocular sporangia steadily until the 
spring when they shew unilocular sporangia here and 
there in the same sorus as plurilocular sporangia. The 
newly developed summer plants may produce a few 
plurilocular sporangia at first but they very soon 
devote themselves exclusively to unilocular sporangium- 
production. 
The life-history of Asperococcus fistulosus has been the 
subject of extended study by Miss H. M. Blackler whose — 
results are incorporated in abbreviated form in this memoir. 
