734 SUMMARY OF CURRENT RESEARCHES RELATING TO 



archegonial plants which continue their growth for some months. 5. Pure 

 males result, in so far as is known, under good cultural conditions from 

 the dominance of the male tendency in the spore over the female 

 tendency. 



Sporangium of Lycopodium pithyoides.* — A. G. Stokey gives an 

 account of the sporangium of Lycopodium pithyoides, a rare species which 

 presents some peculiarities. The stem apex is flattened ; the sporangia 

 are foliar in origin, but owing to displacement become cauline at maturity. 

 They are very large and resemble those of L. dichotomum. The stalk is 

 short. The leaf-trace bends out to the leaf without approaching the 

 sporangium. The sporangium resembles that of L. dichotomum in the 

 number of its wall-layers, four above, six to eight at base. Further 

 details are added. 



Tubers of Polypodium Brunei.! — G. Senn gives an account of the 

 tubers of Polypodium Brunei collected by Werckle in Costa Rica. The 

 tubers much resemble those of P. bifrons Hook, described by Ule in 

 1906. They are rounded hollow bodies with chambers ; they spring 

 from the rhizome and bear rootlets. Morphologically they are homo- 

 logous with the tubers of Nephrolepis tuberosa. In their organization 

 (opening, hollowness, chambering) they agree with the tubers of Myr- 

 mecodia echinata ; and biologically they function exactly like the pitchers 

 of Dischidia Rafjiesiana, which, however, are transformed. Their original 

 function is the storage of water, and their being inhabited by insects is 

 secondary, and is not directly connected with the biology of the plant. 



Apospory and Apogamy in Trichomanes.f — P. G-eorgevitch gives 

 an account of the apospory and apogamy of Trichomanes Kaulfussii, a 

 subject already treated by F. 0. Bower twenty years ago. Georgevitch 

 confirms all that Bower described, but adds further details of the develop- 

 ment of the gemrnas and a description of the antheridia formed upon the 

 shoots that arise from the o'emmae. 



& v 



Lastrea remota.§ — W. B. Boyd gives an account of a fern collected 

 by him in 1894 on the side of Loch Lomond, where it grew in the imme- 

 diate vicinity of Lastrea Filix-mas var. paleacea and L. dilatata. It has 

 been pronounced by some experts to be identical with the Lastrea remota 

 found by F. Clowes at Windermere in 1859, and described by T. Moore 

 after a comparison with authentic specimens of Aspidium remofum Braun 

 from Germany. Braun and Moore regarded the plants as hybrids. Upon 

 this point copious extracts from various authors are given ; and the con- 

 clusion arrived at by the author is that the Windermere plant is a hybrid 

 between /.. Filix-mas and L. spinulosa, while the Loch Lomond plant 

 is a hybrid between L. Filix-mas and L. dilatata. 



Scotch Ferns. || — J. J. Macdonald publishes a list of twenty-one 

 species and three varieties of ferns found in the Comrie district. 



* Bot. Gaz., 1. (1910) pp. 218-20 (pi.). 



t Verb. Naturf. Ges. Basel, xxi. (1910) pp. 115-25 (figs.). 



% Jahrb. wiss. Bot., xlviii. (1910) pp. 155-70 (figs.). 



§ Trans. Edinburgh Field Nat. and Micr. Soc, vi. (1909) pp. 85-92. 



|| Op. cit., vi. (1908) p. 19. 



