Magazine of Natural History. 489 



chapter he explains how these interesting algae are propagated by gemmules 

 analogous to the buds of more perfect plants ; and another is occupied with a 

 detail of observations, which prove that they also produce seeds or at least semi- 

 nal bodies, the result of a union between two or more individuals which con- 

 nect themselves in the same way that the Zygnema? have been long known to 

 do. It seems that these lowest plants have their seasons too of semination, — 

 the reproductive unions occurring only at two seasons of the year, viz. in April 

 and June, but it is probable that the time will depend on the annual temperature 

 of the place which is made the scene of observation. The gemmules are nume- 

 rous and small, while the seeds are very few in number and large, so that were 

 the Closteria to be left dependent on the latter solely for their diffusion or 

 existence, they would speedily become extinct, two individuals being required to 

 produce one fertile seed. No single Closterium can form a seed of itself ; a pair 

 is necessary, and yet each element of this pair, enclosing all the organic con- 

 ditions necessary to reproduction, is in fact an hermaphroditical being. In 

 each there are two utricles with reddish spherules — the male organ, — and two 

 masses of chromules — the female organ. If it remain single, the spherules fe- 

 cundate the divisions of these parenchymatous masses, which become then the 

 gemmules; if it unites itself to another individual, the spherules fecundate the 

 whole and undivided masses of the same chromule, which, by a force acting from 

 the circumference to the centre, is raised to the condition of a seed. Morren con- 

 cludes his paper with the following corollaries — " 1°. II y a des etres chez les- 

 quels les organes de la nutrition forment seuls et a-la-fois les organes reproduc- 

 teurs et les etres reproduits." — " 2°. La formation des embryons vegetaux, 

 dans les algues, depend d'une concentration de la matiere organisee." — " 3°. Les 

 embryons vegetaux chez les algues, se formant sous l'influence d'une force or- 

 ganisatrice qui precede de la circonference an centre." — — Montagne sur les 



plantes cryptogomes recemment decouvertes en France Spach, Conspectus 



Monographic^ Hypericacearum. The following table exhibits a distribution of 

 the British species according to Spach's views : 



Tribus Desmostemone^e — Sectio Elodeine^e. 



Genus Elodes : sp. E. palustris. 

 Tribus Hyperice^e — Sectio Hyperine;e. 



Genus Hypericum : sp. * Holosopalum — H. humifusum. H. quad- 

 rangulum. * * Milleporum — H. perforatum. H. dubium ? * * * 

 Adenosepalum — H. pulchrum. H.montanum. * * * * Droso- 

 carpium — H. Carbatum. 

 Tribus Hyperice-e — Sectio Andros^mine-s:. 

 Genus Androscemum sp. A. officinale. 

 Genus Eremonthe : sp. E. calycinum. 

 The remaining articles of the number consist of short reviews and extracts from 

 the " Flora," and do not require in consequence to be indicated in this place. 



The Magazine of' Natural History. Conducted by J. C. Loudon. 

 Vol. ix. Nos. for Nov. Dec. (Continued from p. 403.) 



I. Zoology. 

 Westwood on the Nomenclature of Natural History, p. 561. We are at the 

 very antipodes with Mr W. on this subject, which it appears to us has been 



