640 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Characese. 
Rabenhorst’s Cryptogamic Flora of Germany (Characeae). — An 
admirable monograph of the Characese of Germany, Austria, and Swit- 
zerland, by Dr. W. Migula, has been commenced as a section of this 
work, four parts being now published. It commences with a very full 
account of the morphology and history of development of the family, 
which the author regards as a primary division, distinct from Algas on 
the one and Muscinem on the other hand. He suggests that their origin 
may possibly be in the Chlorophyceae near to Coleochaete , the Characese or 
Charophy ta and the Bryophyta being two distinct branches. The family 
is, as usual, divided into the two sub-families Nitellese and Chareae, the 
former comprising two genera, Nitella and Tolypella , and the latter four, 
Tolypellopsis, Lamprothamnus, Lychnothamnus, and Chara. The third 
part is occupied by the species and sub-species of Nitella , thirteen 
species being described, and a large number of sub-species, some of 
which are also figured. The fourth part is devoted chiefly to the six 
species of Tolypella, which are treated with equal detail, and with the 
most thorough knowledge of the subject ; it contains also the diagnosis 
of the sub-family Chareas and of the new genus Tolypellopsis (v. Leonh.) 
Mig., in which there is no cortication of the stem or leaves and no 
stipular structures, but in their place a stronger development of three 
small cells of the node ; the leaves have only one or two nodes, and the 
leaflets are often entirely suppressed. The antherids are sessile and 
solitary on the ventral side of the leaf ; the oogones occupy the same 
position, solitary or in pairs, with a very short pedicel-cell ; the neck- 
portion of their cortical cells is elongated into a beak ; the crown small, 
composed of narrow cells, not erect, and narrowing at their apex. The 
illustrations throughout are copious and exceedingly clear. 
Algae. 
Formation of Vacuoles in Algae.* — From observations made on the 
mode of formation of the vacuoles in the reproductive cells of a large 
number of Algae belonging to different families, Herr F. A. F. C. Went 
confirms his previous conclusion that they are formed only as the result 
of the division of vacuoles already in existence. The different modes 
may be arranged under various heads. 
To the first group belong the tetrasporanges and carpospores of the 
Florideae, the tetrasporanges of Dictyota, and the oogones of the Fucaceae. 
When young these cells contain a parietal layer of protoplasm, with 
cliromatophores, often arranged round the nucleus, which is hung up in 
the centre of the large vacuole by threads or plates of protoplasm. The 
vacuoles decrease in size and increase in number by the multiplication 
of these threads or plates, the cliromatophores increasing in number at 
the same time by division. On germination the vacuoles and chromato- 
phores distribute themselves through the newly formed cells, so that 
each cell of the young alga contains only one or a few of them. 
The second group includes those cases where a remnant of the 
protoplasm and of the vacuole remains over as a central vesicle, as in 
* Jahrb. f. Wiss. Bot. (Pringsheim), xxi. (1800) pp. 299-306 (4 pis.). Cf. this 
Journal, 1889, p. 074. 
