740 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Measures, and adds a note on the systematic position of Spencerites, 

 The cone of Mesostrobus Scottii differs from that of Lepidostrobus in 

 Laving the sporangium attached to the distal half of the horizontal 

 portion of the sporophyll, and the ligule is relatively larger and set in a 

 deep pit. 



Genus Ceratopteris.* — R. C. Benedict publishes a preliminary re- 

 vision of the genus Ceratopteris, a complicated group of hydrophytic 

 leptosporangiate ferns, which vary considerably not only in leaf -form and 

 habit, but also in the more fundamental characters of the sporangium, 

 but have till recently been regarded as but a single species. The author 

 has discovered that the number of spores per sporangium varies with the 

 different species, and that this variation and the variation in the de- 

 velopment of the annnlus can be correlated with the variation in leaf- 

 form. The following four species are defined : G. thalictroides Brongn., 

 G LocJcharti Kxrnze, C.pteridioides Hieron., and C. deltoidea, a new species. 



Stigmatopteris, a new Genus of Ferns. t—C. Ohristensen gives an 

 account of Stigmatopteris, a new genus of ferns, in which he brings to- 

 gether twelve South American species closely related by certain cha- 

 racters which have not hitherto been considered as of generic value. 

 They are all exindusiate, and belong to the old genus Phegopteris, and 

 are most nearly related, not to Dryopteris, but to Phanerophlebia. The 

 common characters of all the species of Stigmatopteris are as follows. 

 The lamina is pellucid-punctate, with immersed yellow glands, and desti- 

 tute of hairs ; the stipes, rachis, and costas are squamose ; the veinlets 

 are free or more or less anastomosing, and do not reach the margin, 

 but end in a clavate apex (" hydathode ") ; the long acuminate apex 

 of the pinnae is sharply serrate to its very tip ; and, finally, though 

 tropical ferns are rarely infected by parasitic fungi, yet most specimens 

 of Stigmatopteris are injured by a black incrusting fungus (Parmidaria 

 stigmatopteridis). The author gives an annotated enumeration of the 

 species, with figures, and a key. The species are separable with difficulty, 

 but fall into two groups. 



Galls on Ferns. $ — K. Giesenhagen describes and figures two in- 

 stances of galls on ferns — on Hymsnophyllum lineare var. brasiliense and 

 on H. Ulei— pointing out the parts affected and the nature of the 

 deformation. They are both caused by the larvas of different species of 

 Diptera. Galls on ferns are of very rare occurrence. 



Bryophyta. 



(By A. Gepf.) 



Fertilisation in Marchantia.§— K. Gehrmann writes on the phy- 

 siology of fertilisation in Marchantia polgmorpha, calling attention in 

 particular to the epidermal papilla? on the upper surface of the female 



* Bull. Torrey Bot. Club,xxxvi. (1909) pp. 463-76 (3 figs.), 

 t Bot. Tidsskrift, xxix. (1909) pp. 291-304 (figs.). 

 \ Ber. Deutsch. Bot. Gesell., xxvii. (1909) pp. 327-34 (pi.). 

 § Tom. cit., pp. 341-8 (figs.). 



