INVERTEBRATA, ORYPTOGAMIA, MICROSCOPY, ETC. 829 



B. ORYPTOGAMIA. 



Cryptogamia Vascularia. 



Prothallia of Ferns.* — Professor J. Sachs publishes, in the form 

 of a supplement to the ' Botanische Zeitung' for 1880, 6 plates, com- 

 prising 120 figures, illustrative of the devcloiiment of the prothallia 

 of various ferns, found among the papers left by the late lamented 

 young botanist Dr. H. Bauke. The following are the species illus- 

 trated : — Platycertum grande, Lygodium japoniciim, Gijmnogramme 

 tartar ea, G. L' Herminieri, G. decomposiia, Asjjlenium plantagineiim, 

 Allosorus rotundifolius, Davallia pyxidata, and Hemitelia gigantea. 

 Thero^is no accompanying letterpress. 



Non-Sexual Reproduction of the Prothallium of Ferns by 

 means of Gemmae or Conidia.f — It has been recorded by many 

 observers that the prothallium of ferns can increase by the separation 

 of normal branches formed at the apex, as well as more frequently by 

 that of adventitious shoots detached from the margin or surface. 

 Tuberous swellings have also been observed on the prothallium of 

 Gymnogramme and Hymenophyllum, but their detachment and germi- 

 nation have not been followed out. 



Professor Cramer now records the formation of true non-sexual 

 reproductive organs on the prothallium of an (unnamed) tropical fern. 

 The prothallia having been kept for some time in a watch-glass with 

 water, produced green filamentous excrescences, which were found on 

 examination to be confervoid prothallia furnished with sexual repro- 

 ductive organs and with abundance of gemmae or conidia. The whole 

 confervoid structm'C was from 1 to 1 • 5 cm. in thickness ; the separate 

 filaments were partly expanded flat on the substratum (herpoblasts of 

 Cramer), partly growing in an ascending direction (orthoblasts). 

 Antheridia were frequently observed on them, archegonia only twice. 



The gemmfB were produced especially at the extremities of the 

 orthoblasts. When fully developed they had somewhat the form of a 

 Clostcrium, consisting of a curved row of six or eight or more cells 

 rich in chlorophyll and starch, and of a bright green colour. In 

 course of time they became detached, and in some cases gave birth to 

 secondary gemmae ; in other cases they directly bore antheridia. 



Professor Cramer comjjares this production of secondary proto- 

 nema-like prothallia in ferns to a similar well-known phenomenon in 

 Heimtica). From a phylogcnetic point of view he considers that it 

 indicates the origin of vascular cryptogams and mosses by parallel 

 lines of descent from algoid plants, rather than the direct descent of 

 tho former from tlie latter. 



Amphibious' Nature of the Prothallium of Polypodiaceae.J — 

 Dr. A. Dodel-Port describes tho jieculiar behaviour of prothallia of 

 Asjndinm Jillx-viaa and violasccus wliich ho had kt^pt for a kngthened 



* Ana dcm botauischen Nachlasse von Dr. H. Baukc ; supplement to ' Bot. 

 Zeit.,' xxxviii. (1880). 



t ' Deiikschr. Sdnvoiz. Nuturf. Ges..' xxviii. (1880). 

 i 'Kobinos,' iv. (1880) p. II. 



