154 
GENETIC RELATIONS OP ALG^. 
developed the Glceocapsa or Glcecystis foim with several gelatinous 
envelopes; the CAroococcws type, when the investment is altogether 
wanting, or when there is only a single vesicular envelope, the 
cienobiiim types. The Glceocapsa type is specially adapted for 
exposure to the air, and growth upon a comparatively dry sub- 
stratum ; the caenobium type is developed in water; the Ghroo- 
cocciis type in water, or on a moist substratum in the air. With 
this is connected the cylindrical form, a higher stage, because it 
displays a differentiation in the direction of growth, and a develop- 
ment towards the filiform condition. This is not always developed, 
and may be distinguished into stable and unstable forms ; the latter 
may occur in two or three varieties, and may go through the follow- 
ing successive conditions : — 
1. — Stable Aphanocapsa and Palmella. 
2. — Aphanocapsa and Palmella which have attained to Gloeo- 
capsa, Glceocystis, or caenobium type, but which always revert to 
the naked solitary spherical form. 
3. — Stable Glceocapsa, Glceocystis, Chroococcus, and csenobiiim 
forms, without reversion ( Merismopedia). 
4. — Cylindrical forms, the generations of which pass through 
the solitary spherical (Aphanocapsa and condition, as 
well as the Glceocapsa and similar forms. 
5. — Cylindrical forms which pass through only the Glceocapsa 
and similar forms. 
6. — Cylindrical forms, the generations of which revert to the 
Aphanocapsa and Pcdmella condition, while the Glceocapsa or any 
similar form is suppressed. 
7. — Stable cylindrical forms ( Synecococcus.) 
No reference is made in the above to the passage of Glceocapsa 
into the encysted filiform conditions of Sirosiphon corresponding 
to Palmodactylon and Hcemaspora among the Chlorophyllophyce^. 
There is an undoubted feeling amongst Algologists in favour of 
some such relationship as that indicated by Richter, and any satis- 
factory demonstration of such genetic connection in the Phyco- 
chromacece and the Chlorophyllophycece, would obtain adhesion. 
CRYPTOGAMIC LITERATURE. 
WoLLNY, R. Die Meersalgen von Heligoland, in “ Hedwigia” 
1 and 2, 1881. 
Nylander, W. Addenda nova ad Lichenographiam Europeeam, 
“Flora,” No. 1, 1881. ' 
Richter, P. Form cycle of Glceocystis in “ Amer. Mon. 
Micr. Journ.,” Feb. 1881. 
Winter, Dr. G. Rabenhorst’s Kryptogamen Flora, Pilze, 
Part 2. 
Saccardo, Dr. P. A. Bibliografia della Micologia Italiana, 
in “ Michelia,” No. 7. 
Saccardo, Dr. P. A. Fungi Yeneti, part xii, in “ Michelia,” 
No. 7. 
