276 BOTANICAL GAZETTE [april 



heretofore attributed to respiration, was confirmed. But it is clearly shown that 

 the fixation of oxygen and the evolution of CO3 have no relation to the life of the 

 seed, and that a direct oxidation probably takes place with equal activity in live 

 and dead seeds. Thus the gaseous exchanges of the integuments, compared with 

 those of the decorticated seeds from which theycame, were frequently, weight for 

 weight, very much larger. Further, these exchanges in the isolated integimients, 

 compared with those of the entire seeds of the same species whose integuments 

 are impermeable, are absolutely the same. Where the integument is permeable, 

 however, the gaseous exchanges of the embryo are added to those of the integu- 

 ments. None of these changes take place unless the air is moist and the proto- 

 plasm contains still a certain proportion of water. 



Becquerel has also shown that no perceptible gaseous exchanges take place 

 in the embr}^o when completely dehydrated, and that it can bear for a long time 

 an atmosphere of carbonic acid, nitrogen, or a complete vacuum without losing 

 its power to germinate. In fact, he is convinced that the loss of germinative power 

 is dependent upon the changes permitted by the hygroscopicity of the seeds, and 

 the only ones in which longevity is to be looked for are those with an impermeable 

 integument. 



Incidentally he discusses the longevity of seeds in exlenso, and himself made 

 experiments upon almost 500 species, belonging to 30 of the most important fami- 

 lies of monocots and dicots, whose age was accurately known from the records 



Museum d'Histoire Naiurelle of Paris, Only four families had any \^able 



seeds. 



Legu 



Nelumbium (56 to 18 years), one Lavatera (64 years), and a Stachys (77 7^^^^^ 

 germinated. 



Becquerel seems to have reduced the question to this dilemma: since there 

 is no appreciable metabolism for as much as two years' time, in perfectly dry^ yet 

 \'iable seeds, either their life-processes are wholly anaerobic, intracellular, and very 

 slow, or life is completely suspended. He has begun an experiment of ten years 

 duration to determine whether the dried protoplasm is stable in a vacuum as 

 perfect as can be obtained. He has inclosed in exhausted \ials dry seeds of 

 buckwheat and of wheat, with perforated integuments. These ^^als will be kept 

 in darkness and will be examined with a spectroscope for gases everj- year, and 

 at the end of ten years the seeds will be planted. This experiment promises *- 

 be a crucial one, if (as is to be expected) no gases are set free, and the seeds hvc 

 If it turns out other\vise, the choice between retarded life or suspended life for 

 seeds will remain a speculative one.— C. R. B. 



Apogamy and apospory in ferns.— Helene Woronin,^ working in Goebel's 

 laboratory, has published the results of an experimental study on apogamy and 

 apospory in ferns. The study included six species; Trkhomanes Kraussih 

 Pellaea flavens, P. nivea, P. tenera, Nolochlaena Eckloniana, and N. siniiata. 



to 



8 WoRONiN, Helexe, Apogamie und Aposporie bei einigen Farnen. Flora 98: 



IOI-162. figs. J2. 1907. 



