The Cytology of two Species of Characiopsis. 179 
with the alga in question. In all other characters than shape, 
the elongated and irregularly shaped cells are identical with each 
other, even in the cytological details of the cell-structure, and 
there is not the slightest doubt that these individuals of peculiar 
form are to be considered merely as abnormally developed 
specimens. 
Characiopsis saccata sp. n. Cellulae adultae plerumque elon- 
gatae cylindricae vel subfusiformes, apice acuminato, stipite brevi 
discoque basali prteditae, juniores saepissime forma irregular! 
quinetiam triangulari, chromatophoris copiosis vel prima juventute 
singula, parietalibus, foliorum ad instar tenuissimis; cytoplasmate 
grosse granuloso, nuculeis 1-32. 
Long. 15-82 
Lat. 4-16/x. 
Hab. in foliis Quercus emortuis, Pool Hollies Wood, Sutton 
Park. November, 1918. 
Cytology. 
In 1895 Borzi established the genus Characiopsis to include 
a number of epiphytic algae previously described as species of 
Characium. The distinguishing features of Characiopsis are the 
presence of usually two or more parietal chloroplasts, the absence 
of pyrenoids and starch, and the storage of oil. Characiopsis thus 
belongs to the HeteroUontae, whereas Characium belongs to the 
Protococcales. Later Lemmermann (T4) removed a number of 
other species from Characium on these grounds, and placed them 
in Characiopsis. Nevertheless it is true that the two genera 
greatly resemble each other, and there is undoubtedly some con¬ 
fusion with regard to them. Thus it was hoped that the examination 
of these two species of Characiopsis , Ch. Ncegelii and Ch. saccata, 
and the comparison of them with an undoubted species of 
Characium would help to clear up the misunderstanding which 
at present exists concerning these two genera. 
Methods. The algae were fixed in a hot solution of corrosive 
sublimate consisting of— 
Corrosive sublimate ... 3 gins. 
Glacial acetic acid ... 3 ccs. 
50 % Alcohol ... ... 100 ccs. 
The material was first washed in 50% alcohol, and finally in 
alcohol to which a little iodine had been added. It was taken down 
to water and stained in Heidenhain’s iron haematoxylin, and 
finally mounted in Venetian turpentine. In the case of the 
sections the epiphytes were fixed in situ on the leaf on which 
they were living, the leaf being finally embedded and sectioned. 
