Morphologie etc. — Varietäten, etc. 179 



neously develop into complete embryosacs. The embryosac is 

 tetranucleate, lacking the antipodals and one et" the polar nuclei. 

 The pollen-tube enters the synergid through the filiform apparatus 

 and the mixed plasma flows out through the synergid and spreads 

 over the oosphere. The male nucleus is enclosed in a distinct 

 plasma sheath, until it reaches the oosphere. One of the male 

 nuclei fuses with the pole nucleus, and gives rise to the endosperm 

 nucleus with diploid number of chromosomes. 



Tetranucleate embryosacs do not only occur in Oenothera but 

 are found in Ludwigia, Gaura, Godetia and Circaca. The author 

 regards the tetranucleate embryosac as a diagnostic character of 

 the Onagraceae, and considers that Trapa, which has a normal 

 8-nucleate embryo-sac should be separated from the Onagraceae. 



The author enumerates and discusses all the known cases of 

 4-nucleate and 16-nucleate embryo sacs. He concludes that these 

 aberrant embryo-sacs all belong to plants whose habit is herba- 

 ceous, and he considers that this harmonises with the view ofjef- 

 frey's school that herbaceous plants are more highly evolved than 

 Woody plants. Agnes Arber (Cambridge). 



Harris, J. A., Further observations on the selective eli- 

 mination of ovaries in Staphylea. (Zschr. ind. Abst.- u. Ver- 

 erb.-Lehre. V. p. 173—188. 1911.) 



The purpose of the paper is to obtain, through the analysis of 

 the records of over 8000 fruits of Staphylea trifoUa, further light 

 on the Problem of the selective elimination of ovaries which occurs 

 between the time of flowering and the maturing of the fruits. As 

 in most biological researches, the degree of precision oftheresults 

 is limited by both the nature of the material and the number of 

 observations which are practicable. There are difficulties inherent 

 in the material and the relationships determined are generally so 

 low that too much dependence cannot be placed upon the calcu- 

 lated probable errors. The author lay no stress whatever on the 

 exact numerical results. Bearing in mind probable errors, they 

 are very consistent throughout. The correlations between the Po- 

 sition of the fruit on the infiorescence and the characters of the 

 fruit are low. Sometimes it is even irapossible to be sure of the 

 sign of relationship. The data and analysis described above throw 

 no doubt upon the conclusions drawn in an earlier memoir on the 

 selective elimination occurring during the development of the ovar}^, 

 but tend to make them more significant by showing that apparently 

 they are not to be explained by a combination of such simple fac- 

 tors as a differentiation of the ovaries associated with their position 

 on the infiorescence and a proportionately higher but random eli- 

 mination in the more distal region of the infiorescence. Probably, 

 however, the slight differentiation of ovaries with respect to Posi- 

 tion on the infiorescence does account for some of the difference 

 between eliminated and matured ovaries. The difference in mean 

 number of ovules may be in part due to this cause. There is no 

 evidence that the results announced for radial asymmetry or locu- 

 lar composition can be explained in any other way than that ova- 

 ries with the higher grades of asymmetry with an excess of „odd" 

 locules have a lower capacity for development. 



Matouschek (Wien). 



