494 Physiologie. — Algae. 



Ugolini, U., Sag gl o di studi sulla vita iemaie delle piante. 

 (Commentari Ateneo di Brescia. 1905. p. 79 — 127.) 



L'^tude soignee des phdnomfenes exterieurs de la vie chez 

 plusieurs plantes parmi les plus caracteristiques ä cet ^gard, 

 montrent que dans nos pays les ph^nomfenes dpig^s de la vie sont 

 arret^s pendant l'hiver chez la plupart des plantes (plantes post- 

 c h i m fe n e s) ; cependant certaines (plantes Sedum maximiim Sut., 

 Medicago sativa L. etc.) commencent en automne une nouvelle 

 Periode v^gdtative qui s'arrete pendant l'hiver (plantes achei- 

 matobies ou subacheimatobies). Par contre chez d'autres 

 plantes la vie est plus ou moins active et intense aussi pendant la 

 mauvaise saison (plantes cheimatobies), soit qu'elles com- 

 mencent la nouvelle p^riode vdgdtative en hiver (plantes chimfenes 

 [p. ex.: Miiscari comosum Mill., Campanala rapiinculoides L,, C. 

 Trachelium L.]), soit avant l'hiver (plantes pr^chimenes [p. ex.: 

 Bl^, Anim italiciim Mill., Anemone Pnlsatilla L., Almis glutinosa 

 Gaertn., Narcissus Tazetta L.]). Chez les plantes cheimatobies 

 l'intensit^ de la vie est non seulement attenude en hiver, mais aussi 

 discontinue et oscillante gräce ä cette merveilleuse adaptation qu'ont 

 les plantes de profiter de chaque circonstance si petite qu'elle soit, 

 favorable pour la manifestation de leurs phdnomfenes vitaux. 



R. Pampanini. 



Sheldon, John L., Tubercles on Legumes with and without 

 Cultures. (West Virginia Agr. Expt. Stat., Bull. CV. June, 

 1906. p. 319—334.) 

 The results are given of tests to determine whether the arti- 

 ficial cultures of the tubercle-forming bacteria were of any value for 

 inoculating the seeds of different legumes. Cultures of the spe- 

 cific forms for alfalfa, red clover, vetch, soy bean, cow-pea and 

 velvet bean were used. It was found that the control plots, as well 

 as those that were inoculated, contained tubercles on the roots of 

 the plants. Only one out of fifteen species of legumes which were 

 planted in a certain soll did not have tubercles. The experiment 

 seemed to indicate that in this locality inoculation is not necessary. 



Hedgcock. 



Yamanouchi, Shigeo. The Life History of Polysiphonia violacea. 

 (Botanical Gazette. Vol. XLI. 1906. p. 425—433.) 



This is a preliminary announcement of the results of a cytologi- 

 cal study of Polysiphonia. 



The nuclei of the germinating carpospore and of the tetrasporic 

 plant each contain 40 chromosomes, and so it may be inferred that 

 the tetrasporic plants come from carpospores. The nuclei of the germi- 

 nating tetraspore and of the sexual plants each contain 20 chromo- 

 somes, and the inference is that sexual plants come from tetraspores. 

 The nuclei of the sperm and carpogonium contain 20 chromosomes, 

 and the fusion nucleus 40 chromosomes. 



The fusion nucleus gives rise to a series of nuclei, some of 

 which enter the carpospore. The formation of the tetraspores termi- 

 nates the sporophytic phase with typical reduction phenomena. There 

 is thus an alternation of sexual plants (gametophytes) with tetra- 

 sporic plants (sporophytes) in the life history of Polysiphonia. 



Charles J. Chamberlain (Chicago). 



