1894.] A Biue-Green Motile Cell. 99 
treated with dilute potassic hydrate solution to destroy the 
chromatophores and then stained with eosin. 
In several instances, while examining under the microscope 
the colonies scraped from the marsh grass, single cells were 
observed to slip out from the colony and swim away and these 
were identical with the blue-green motile cells. 
Taxonomy. 
The, presence of a well defined nucleus, pigment spots and 
chromatophores clearly showed that this form was not a, 
member of the Myxophycez as the group is defined by most 
botanists. 
Of late there has been considerable discussion on the inner 
structure of the cells of Myxophycee, particularly in respect 
to the possible occurrence of. nuclei and chromatophores. 
Almost all the investigators in this field of research agree in 
saying that there never exists a nucleus in the usual sense of 
the word; that, if present at all, it is in the form of some cen- 
tral body of very indefinite outline, or scattered through the cell 
in the shape of small granules which react with stains in a 
Manner similar to the chromatin bodies in the nuclei of higher 
plants. The nucleus in the present form is perfectly well de- 
fined and contains a distinct nucleolus. In regard to the pres- 
ence of chromatophores in the cells of Myxophycez there is 
less unanimity of opinion among recent writers. Several in- 
vestigators, Hieronymus, Zukal, and others, believe that 
chromatophores exist; but other investigators, Zacharias in 
Particular, have not been able to find them. ‘The chromato- 
pe of Hieronymus is present as a network just under the 
ne and is only made apparent by special treatment. No 
“i canal appears to have seen bodies as definitely organ- 
ro = outlined as the chromatophores in the cells of the 
the aon. has just been described. For a general review of 
es akean ; on this subject the reader is referred to a paper 
Saad ult in the Revue gén. de Botanique 5: 181. 1893. 
1 OE motile cells: have been known for a long time. 
under th § in 1838 published an account of three species 
le genera Cryptomonas and Cryptoglena and since then 
has been added to our systematic knowledge of 
- The genus Cryptoglena was distinguished from 
by Ehrenberg because of its pigment spot, and 
*Ebren| z 
berg, Die Infusionsthierchen als vollkommene Organismen. 1838. 
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