11*0 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of the chromatin linin in the nucleus and by electrical conditions. »>. 

 Chromatic droplets are ejected from the nucleus into the cytoplasm at 

 certain stages of mitosis. 7. Nuclear divisions resembling amitosis 

 occur frequently in the hybrid P. Schneider/', but they also occur rarely 

 in P. vulgare and its var. elegantissimum. These imperfect mitoses are 

 brought about by the failure of the nuclear wall to disappear at the end 

 of diakinesis. 8. Much irregularity as to pairing of the chromosomes 

 to form the bivalents exists in the hybrid plant, and also, though less 

 obviously so, in P. vulgare var. elegantissimum. 9. The processes that 

 lead to depauperation of the reproductive cells, and ultimately to sterility, 

 in hybrids are encountered in certain sports, which also exhibit sterility 

 in a marked decree. 



-■to* 



Aspidium remotum Al. Br.*— H. Fischer discusses the question as 

 to whether Aspidium remotum is the outcome of crossing or mutation. 

 He collected specimens of the plant in the Vosges and raised plants from 

 some of the spores. Some of the material germinated plentifully and 

 the prothallia produced numerous plantlets, but they remained apoga- 

 mous. The apogamy followed the usual lines and showed nothing of 

 special interest ; the upper part of the midrib, near to the apex, grew 

 out into the young plant. The author comes to the conclusion that 

 Aspidium {N&phrodium) remotum is certainly no good species, but also 

 no montrosity ; the question remains whether it is a bastard or has 

 arisen by mutation. The author inclines to the latter view. Whether 

 apogamy is the general result of germination in N. remotum is also an 

 unsolved question. Should further investigation prove that apogamy is 

 typical for N. remotum, then the interesting fact is established that a 

 bastard or a " mutante " has inherited apogamous methods of reproduc- 

 tion, such as we have only known till now in good species or monstrosities. 



The author then discusses certain monstrosities (N.filix-mas monstr. 

 polydactyla Moore and Athyrium filix femina monstr. depauperata r subvar. 

 Edelstenii Lowe) which he has grown under supervision, as well as some 

 other species. He doubts whether Asplenium germanicum Weiss is really 

 a bastard. 



New French Ferns.f — H. Leveille gives an account of two new 

 varieties of French ferns described by H. Christ, Polystkhum (Dryop- 

 teris) fllix-mas var. Pagesii and Asplenium for esiacum var. angustatum, 

 both collected in the department of Herault by H. Coste. 



Pteridophyta of Malta 4 — Gr. Gulia gives a list of the Pteridophyta 

 of the Maltese islands. These comprise fourteen species, the distribu- 

 tion and native names of which are stated. Scdvinia natans depends 

 upon a single record, upon which Sommier casts some doubt in view of 

 the absence of this species from all the Italian islands. 



Studies of Tropical American Fems.§ — W. R. Maxon publishes a 

 second paper on tropical American ferns, with the following chapters :— 



* Ber. Deutsch. Bot. Gesell., xxvii. (1909) pp. 495-502. 



+ Bull. Acad. Internat. G6ogr. Bot., xvii. (1909) pp. vii.-viii. 



J Bull. Soc. Bot. Ital., 1909, pp. 220-2. 



§ Contrib. U.S. Nat. Hist. Herb. Washington, xiii. (1909) pp. 1-43 (pis.). 



