138 SUMMARY OF CUliliENT KESEAIIGHES RELATING TO 



produced parthenogenetic seed without difficulty in species and hybrids 

 of Nicoiiana. The species used for the experiments was a white-flowered 

 variety of N . Tahacum, this being the variety with which Mrs. Thomas 

 was most successful. Previous investigations dealing with over 1000 

 attempts to produce parthenogenetic seed from numerous other species, 

 varieties, and hybrids of Nicotiana gave entirely negative results. The 

 most successful results were those obtained with the above-mentioned 

 variety, where 800 castrations and mutilations of buds produced over 

 100 normal fruits ; but the majority of these parthenocarpic fruits pro- 

 duced merely a large number of empty seeds and a few flattened or 

 shrivelled seeds. The production of such seed may be regarded as a 

 process of phenospermy. About fifty seeds from nine parthenocarpic 

 fruits were, however, found to contain normal endosperm and embryos ; 

 eighteen such seeds produced six seedlings, which have attained a fair 

 size. A small portion of the seed was neither parthenogenetic nor 

 phenospermic, but contained traces of nothing but endosperm. The 

 author is thus able to confirm Mrs. Thomas's results so far as this species 

 is concerned, but his experiments appear to show that parthenogenesis 

 is limited in Nicotiana to this one strain, known as N. Tahacimi Cuba. 



Anomalies in Linaria.*— P. Yuillemin contributes a note upon the 

 anomalous flowers of Linaria. Forty- nine such flowers were examined, 

 and were found to be anomalous in the number and form of the spurs 

 and in the number of petals and stamens ; in the majority the numbers 

 of spurs, petals, and stamens were in excess of those characteristic of the 

 normal flower. This may be the result either of partition or reduction 

 of the parts of the original normal flower. There is no evidence in 

 favour of partition, but rudimentary vestiges of petals in several abnormal 

 flowers favour the view of reduction ; thus the origin of these abnor- 

 malities appears to be a typical decamerous flower. But the normal 

 Linaria flower is of a fixed peutamerous type, so that a decamerous flower 

 can only exist by a union of the buds of two peutamerous flowers. Thus 

 gamogemmy must be regarded as the cause of these anomalies. Such 

 gamogemmy has been shown by the author to be the result of injury of 

 the axis of the inflorescence. 



CRYPTOGAMS. 



Pteridophyta. 



(Bj' A. Gepp, M.A., F.L.S.) 



Hippochaete in North America.! — 0. A. Farwell, after studying 

 the genus Equisetum of the United States, is convinced that the species 

 should be grouped under two genera : 1. Eq^iisetum, with stems 

 annual, often dimorphous, the sterile always with regular verticils of 

 acutely angled branches at the nodes ; spikes rounded at apex ; 



* Comptes Rendus, clxiii. (1916) pp. 382-5. 



t Mem. New York Bot. Garden, vi. (1916) pp. 461-72. 



