ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
829 
common, including several species of Cladophora , Yalonia vegagropila 
and confervacea , and Codiurn mamillosum. Of Cyanophycese may be 
mentioned Stigonema ocellatum (3 globosum, and Hapalosiphon pumilus 
/3 globosus. In addition to these, Prof. Lagerheim describes a form of 
a ChsetomorpJia allied to G. crassa, which forms similar dense globular 
floating masses composed of a large number of filaments interwoven 
together. 
Ectocarpus siliculosus.* — Herr P. Kuckuck describes a variety of 
this alga, on which he bestows the name var. varians , distinguished 
by the remarkable variation in the form and size of the plurilocular 
sporanges. They are either bluntly cylindrical, two or three times as 
long as broad, with bulging chambers, or cylindrico-spherical, or greatly 
elongated, and either sessile or stalked, terminal or intercalary. The 
chromatophores agree with those of the normal form, lying in several 
not unfrequentlv branched bands on the cell-wall. The variety grows 
intermixed with the typical form, and there are all intermediate stages 
between them. 
Saccorhiza.f — Mr. W. A. Setchell has investigated the life-history 
of Saccorhiza dermatodea, and finds that it agrees with the Laminariaceas 
in its general structure. The permanent organ of attachment originates 
from a special organ, the rhizogen, which produces two successive rows 
of hapters ; the first organ of attachment or primitive disc is only 
temporary. The cryptostomates, as well as the tufts of hairs, spring 
from a level surface in the young fronds ; in the parts where the 
structure is more complex they occupy the base of cup- shaped depres- 
sions which are finally bordered by a prominent margin. The pith is 
surrounded by filaments arranged as in other genera of the order : 
special sclerenchymatous fibres are developed in the pith of the stipe 
and leaf. The paraphyses do not possess the curious terminal ap- 
pendage characteristic of the greater part of- the Laminariacese. The 
process of development resembles that of rejuvenescence in the Lamina- 
riaceae. There are no cryptostomates in the adult frond. 
Non-nucleated Cells in the Conjugatae.t — M. J. Gerassimoff states 
that the peculiar state of some species of Spirogyra and Sirogonium, in 
which, of two neighbouring cells, one has two nuclei and the other none, 
may be induced by exposure to a low temperature. The sister-cell of a 
non-nucleated cell may, however, contain only a single nucleus, either 
simple or compound. When there are two nuclei, they always take up a 
position exactly opposite to one another. Non-nucleated cells may also 
be formed, in these two genera of Conjugate, in quite a different way, by 
a cell dividing at once into three cells from the simultaneous appearance 
of two parallel septa. 
Glaucocystis.§ — Herr G. Hieronymus has studied the structure and 
mode of propagation of the rare organism Glaucocystis Nostochinearum. 
He finds that, even in the mature plant, the chromatophores have the 
* Ber. Deutsch. Bot. Gesell., x. (1892) pp. 256-9 (1 pi.). 
f Proc. Ainer. Acad. Sei., xxvi. (1891) pp. 177-217 (2 pis.). 
+ Bull. Soc. Imp. Nat. Moscou, 1892, pp. 109-31 (9 figs.). Cf. this Journal, 1892, 
p. 614. § Beitr. z. Biol. d. Pflanzen (Cohn), v. (1892) pp. 461-71 (1 pi.). 
