194 SUMMARY OF CURREXT RESEARCHES RELATING TO 



and will even produce an abundant supply of both antheridia and 

 oogonia. Apparently a very small number of spores are capable of 

 germination, producing a pro-embryo of characteristic growth. The 

 pro-embryos produced from the oospores resemble those produced from 

 the underground nodes of the plant. In many cases the pro-embryo 

 difiFers from that of other Characeae by the interposition of an extra 

 oblique node, from which rhizoids are produced. In the case of the 

 pro-embryos produced from the rhizoid-nodes bearing tubercles, about 

 30 p.c. showed this interposed node. For the most part reproduction 

 takes place by means of pro-embryos, which are formed on the rhizoid- 

 nodes and make use of the starch stored up in the tubercles. Branch 

 embryos are rare. Sometimes pro-embryos arise from rhizoid-nodes 

 bearing no tubercles, or from the rhizoid-node of another pro-embryo. 

 The tubercles either originate as such, or are formed by the trans- 

 formation of rhizoids. The terminal rhizoid of a tubercle may again 

 become transformed into a tubercle containing starch, thus forming a 

 series of two or more tubercles. The pro-embryos arise at tlie basal 

 side of the tubercle. Generally, several pro-embryos arise from a node 

 bearing tubercles. The nuclei of the tubercles are fragmented, as in 

 the case of the internodal cells. 



Swedish Species of Chantransia.* — H. Kylin describes in detail 

 four species of Ckantramki which occur in Sweden, three of which are 

 new. These are G. pectinata, which in habit resembles C. efflorescens , 

 differing from it in having thicker branches and much shorter ceUs ; 

 C. hallandica ; and C. parvula. G. hallandica is found growing on 

 species of Geramium, Polysiphonia and GalUthamnion at a depth of 

 10-20 metres. Figures are given of all the species described. 



Corsican Moss.f — F. Jadin and J. B. (iargain have examined this 

 commodity, which is used as a vermifuge, and finds that it is a mixture of 

 algae, of which the predominating species is Alsidium Helminthochorton. 

 The material examined was obtained from druggists, and was compared 

 by the authors with specimens collected in the Gulf of Ajaccio. The 

 other alg£e found in Corsican moss were : Jania ruhens ; Gelidium 

 corneum • Padina pavoaia ; and Acetahularia mediterrama. 



Polysiphonia violacea.| — S. Yamanouchi publishes the complete 

 account of his studies on this species, of which he had previously given 

 a short account in the Botanical Gazette. In the present paper he 

 gives first the results of his studies of the mitosis in germinating tetra- 

 spores and carpospores and in the vegetative cells of mature plants ; then 

 comes an account of spermatogenesis, formation of procarp, fertilisation, 

 and development of the cystocarp ; tetraspore formation is then con- 

 sidered, followed by a description of certain abnormalities ; finally, there 

 is a discussion of the cytological phenomena and alternation of generations. 

 This last topic has been given considerable attention, for the chief 

 results of this investiffation have been the establishment of an antithetic 



'53 '^ 



* Botaniska Studier tillagnade. Upsala : P. R. Kjellman, 1906, pp. 113-26. 

 t Bull. Pharmacie du Sud-Est., xi. (1906) 4 pp. 

 X Bot. Gazette, xlii. (1906) pp. 401-49 (10 pis.). 



