1902) | MICROSCOPICAL JOURNAL. 33 
9 
The descriptions of sporocarps and antheridia are very 
full and complete for each species. He relates his mi- 
croscopic manipulations with the specimens as follows: 
On account of the fact that in most of the species of 
Porphyra examined the jelly makes up a large part of 
the frond, considerable difficulty was encountered in pre- 
paring the necessary number of mounts. The specimens 
collected fresh were either dried or killed on the shore 
in Flemming’s mixture, strong and dilute, one per cent 
chromic acid, one per cent, two per cent and five per 
cent chrome alum, Wilson’s corrosive sublimate, one per 
cent formalin and alcohol. Of all these, Wilson’s solution, 
formalin and alcohol, gave the best results, the others 
either shrinking the specimens or failing to fix them. 
As soon as this point was settled, all except the latter 
three were discarded. In some cases, as in P. naiadum, 
formalin gave the best results; while in others, Wilson’s 
solution was to be preferred. 
The necessity of the salt of a heavy metal to fix the 
jelly became apparent when rough dried and herbarium 
specimens were examined. The first ones to be studied 
were dried specimens of P. perforata which, when soaked 
in water, resumed their original outward form. But when 
the same process was tried with others, especially with 
P. variegata, it was found that the jelly dissolved very 
readily, so that some means had to be resorted to by 
which the specimens might be preserved in good condi- 
tion. At first, glycerin, twenty per cent glycerin in 
water, and twenty per cent alcoholic glycerin were tried, 
but without good result. When a saturated aqueous so- 
lution of corrosive sublimate was used cold, this answer- 
ed all requirements in every case except that of P. varie- 
gata, where it was necessary to use a boiling saturated 
aqueous solution. 
Of all species of which fresh material could be obtained 
sections of from three to five microns in thickness were 
