Morphologie, Teratologie, Befruchtung, Cytologie. 83 



from the coast of Lancashire. It wasfound thatwhen plants belonging 

 to the 0. Lamarckiana series of forms were cultivated in the tropica! 

 greenhouse of the Universit}^ of Chicago (i. e. under conditions 

 of high temperature and high humidity) nearly all of them retained 

 their rosette form during the two 5'^ears which the experiment 

 lasted. They threw up no elongated flowering shoots, but new 

 cycles of rosette leaves were continually added above, while the 

 older ones died away below. In this way a short stem was produced, 

 covered with closely placed leaf-bases, Avithout internodes. 



Agnes Arber (Cambridge). 



Georgevitch, P., Preliminary Note on Apospory and Apo- 

 gamy in Trichomanes Kaulfussii, Hk. et Grew. (Ann. Bot. XXIV. 

 p. 233. 1910.) 



Bower observed apospory and the development of gemmae in 

 Trichomanes Kaulfussii. The present author has carried the subject 

 further and investigated the later history of the gemmae. He has 

 also observed apogamy following on the apospory which was 

 previously described, and has ascertained that the number of 

 chromosomes is the same (about 80) in both sporophyte and game- 

 tophyte. Agnes Arber (Cambridge). 



Harris, J. A., A Quantitative Study of the Morphology 

 of the Fruit of the ßloodroot, Sanguinaria canadensis. (Bio- 

 metrika. VII. p. 305—351. 1910.) 



The author points out that the methods of higher statistics, 

 which have at present been chiefly used to throw light upon the 

 Problems of evolution, might well be applied in the fields of mor- 

 phology and physiology. 



As a result of his Statistical study of Sanguinaria he is able to 

 show that the length of the peduncle and the length of the fruit are 

 to some extent interdependent. The number of ovules formed, the 

 number of seeds developing and the number of aborted ovules per 

 fruit are also correlated with. peduncle length. Correlation tables 

 showing the relationship between these and other characters are 

 given in an appendix. Agnes Arber (Cambridge). 



Lawson, A. A., Nuclear Osmosis as a Factor in Mitosis. 

 (Trans. Roy. Soc. Edinb. XVIII. i: p. 137—161. 4 pl. 1911.) 



The writer points out that there are great difificulties in the 

 way of accepting any existing theory which aims at explaining 

 the mechanism of mitosis. He thinks that the cause of many 

 difificulties lies in the fact that important series of stages in the 

 di Vision of the nucleus have been overlooked, — those, namely, 

 of the later prophase, preceding the Organisation of the equatorial 

 plate. These stages are described in the present paper in the 

 course of a study of the microspore mother-cells of Disporunt, 

 Gladiolus, Yucca, Hedera, and the vegetative cells of the root-tip of 

 Alliurn. The author attempts to demonstrate that there is not, at 

 any stage in the mitosis, any breaking down of the nuclear mem- 

 brane, but that in the prophase it gradually closes in until it even- 

 tually envelopes each chromosome separately. Each chromosome 



