ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 57 



of a perforation at the apex of the shell of some forms of Dtjiugia 

 acuminata. The paper is a very welcome contribution to a little-worked 

 field of British Zoology. 



Discoloration of Water by Gonyaulax.* — T. Nishikawa investi- 

 gated streaks and patches of brownish-yellow water emitting an un- 

 pleasant odour in the Bay of Agu in the southern part of the province of 

 Shinia, on the Pacific side of the Hondo. The " red-tide," as it is called,. 

 is due to Gonyaulax polygramma Stein, one of the Peridiniacese (identified 

 by Mr. George Murray), of which there may be 800-3000 in a drop. 

 Nishikawa refers to previously recorded cases of unusual coloration, 

 due to Peridinium sanguineum, Glenodinium rubrum, and Gymnodinium. 

 The appearance of the red-tide is associated with great mortality among 

 fishes, molluscs, shrimps, &c, but it is also certain that the pearl oysters 

 feed upon the Gonyaulax forms as they usually do on Bacillariacese. It 

 is probable that the injurious effects arc indirect. 



Zoospore and Spermatozoon.! — Prof. P. A. Dangeard finds a re- 

 markable confirmation of his theory of sex in the minute homologies 

 which seem to exist between the zoospores of Polytoma uvella and the 

 spermatozoa of various Metazoa. In Polytoma the locomotor apparatus 

 consists of two flagella. At the base of these is a blepharoplast or small 

 thickening of the ectoplasm, which is slightly chromatic. From this 

 there runs towards the nucleus a chromatic thread, to which he gives the 

 name of rhizoplast, which is inserted in the nucleus by means of a little 

 swelling, to which he gives the name of condyle. All these structures 

 are also to be found in spermatozoa, or have been described there by 

 various authors. Dangeard believes that the zoospore of Polytoma is to 

 be regarded as the ancestor of the Metazoon sperm, and considers that 

 the resemblance described above confirms his conclusions. As, however, 

 tbe structures described in Polytoma are mere transitory differentiations 

 of the protoplasm comparable to the flagella, while those of the Metazoon 

 sperm have been ascribed to the centrosome, the author is of opinion that 

 the centrosome of the sperm does not play the important part attributed 

 to it by embryologists. 



Phylogeny of Protists.J — A. Scherffel discusses some of the difficult 

 questions connected with the relationships of the lower organisms, and 

 especially their relation to tbe Alga3 and Fungi. He does not believe 

 that nearly related Protists have independently acquired chromatophores, 

 but maintains that the chlorophyll-containing and colourless forms have 

 followed throughout independent, though it may be parallel, lines of 

 evolution. But at the same time he admits that members of chlorophyll- 

 containing groups may lose their chlorophyll, as an adaptation to special 

 conditions. Examples of such forms are the colourless forms of the 

 Euglenoids, the Polytoma? among the Volvocinse, and so on. 



Silicoflagellate Protozoal — E. Lemmermann has obtained from 

 various sources plankton nettings containing specimens of the organisms 

 described by Borgert as Silicoflagellata, and gives a summary account of 



* Annot. Zool. Japon, iv. (1901) pp. 31-4. 



t Le Botaniste (Dangeard), vii. (1901) pp. 269-72 (3 figs.). 



% Bot. Ztg., viii. (1901) pp. 143-58 (1 pi.). 



§ Ber. Deutscli. Bot. Ges., xix. (1901) pp. 247 71 (2 pis.;. 



