BOOK-NOTES, NEWS, ETC. 339 



that " too many slight varieties are alleged " — Epilobium, Hiera- 

 ciwn,Anagallis, Euphrasia, Mentha, Salicornia, Polygonum, Ulmus, 

 and Potamogeton — are numerous, and must not be overlooked by 

 workers. We are glad to note that Mr. Oyer speaks well of the 

 specimens sent in ; these reached the unprecedented total of 

 8656 — a gratifying indication that the interest in British botany 

 is not diminishing. 



BOOK-NOTES, NEWS, dx 



In 1909 an interesting note was published in the Tokyo 

 Botanical Magazine by Mr. M. Tahara, on the liberation of 

 oogonia in species of Sargasswn, as the result of his studies at the 

 Misaki marine biological station. In this note he gives his 

 opinion that the liberation of oogonia in Sargasswn " takes place 

 simultaneously, not only for a given plant but also for all plants 

 of the same locality"; and he further states that "this simul- 

 taneous liberation proceeds in fortnightly crops on a particular 

 day, with a fixed interval after the highest spring tide, the interval 

 varying, however, in different species." Owing to the relative 

 shortness of time during which he was able to study these 

 phenomena, Mr. Tahara returned later to Misaki and renewed his 

 observations on Sargasswn enerve, S. Horneri and Cystophyllum 

 sisymbrioides. His results are published in the Journal of the 

 College of Science, Tokyo (vol. xxxii. 1913, art. 9, 13 pp. 3 plates), 

 where he shows that, although the intervals between the two 

 corresponding liberations in Sargasswn enerve and S. Horneri are 

 tolerably constant, the intervals between two successive libera- 

 tions is quite irregular ; for example, in S. enerve it may be 5, 6, 

 9, 10 or 11 days, and therefore bears no fixed relation to the 

 highest spring tide. A study of each species shows the same 

 result. Thus the phenomena of the liberation of oogonia in 

 Sargasswn and Cystophyllum differ from those in Dictyota dicho- 

 toma, in which species their relation to the highest spring tide is 

 an established fact. The author goes on to describe the different 

 modes in which the oogonia are liberated in Sargasswn Horneri and 

 in Cystophylkcm sisymbrioides, and the part played in each by the 

 paraphyses. In discussing the early stages of embryogeny, the 

 author alludes to Miss Simon's paper on Sargasswn filipendula, in 

 which she states that the three successive nuclear divisions before 

 oosphere formation, common to Fucacia, are suppressed in that 

 species. He paid special attention to this point in species of 

 Sargasswn and Cystophyllum, and he finds the oogonium develop- 

 ment quite normal. The development of the sporelings in these 

 genera is described in detail. — E. S. G. 



The Journal of the Boyal Horticultural Society for August 

 (xxxix. pt. 1) contains the papers read at the Primula Conference 

 held in April last. These include Dr. John Mac Watt's paper 

 on " European Primulas," Mr. Eeginald Farrer's on " Primula 

 Hybrids in Nature," and Prof. Balfour's on " Chinese Species of 



