FERN GROWING 35 



microscopic observations had established the possibility of 

 multiple fertilisation in Ferns." * 



Professor Bower, F.R.S., said "this inquiry had now arrived 

 at the stage when it might be put to a vigorous test. Perhaps 

 the best way would be to cultivate certain ' prothallia, ' 

 and then to actually follow the whole process of development 

 through, under the microscope. The next step would be to 

 proceed in the same way as with fungi. He thought the 

 views put before the conference that afternoon would make 

 any man take the subject in hand to investigate." 



Dr. Stansfield, of Reading, said "he had experimented 

 in the same way as Mr. Lowe with spores of the Axminster 

 variety (of the Lady Fern), with the result that a multiple 

 character was produced. The spores were sown together, 

 and great variety was shown in the progeny. Not only 

 was cresting developed in the pinnules, but instead of a 

 flat crest a round one was obtained. Another result different 



* There are so many difficulties to be surmounted in a microscopic examination, 

 that it may be years (if ever) before the microscope discloses multiple parentage 

 in Ferns. The author has tried it himself and failed. One of the difficulties is 

 the absolute necessity of thick sowing, for when prothalli do not touch each other 

 we cannot obtain a cross ; and if we grew them separately, and then brought two 

 or three others, and planted them so that they overlapped, the facilities would not 

 be increased, as there must still be the difficulty of a clear view ; and the organs 

 of generation might not be in a proper condition at the same time. 



Then again, so few are the instances of multiple impregnation in comparison 

 to the number of spores sown, that a thousand distinct microscopical investigations 

 might not yield a single example. It is no doubt desirable to repeat the attempt, 

 as this might be observed ; but a negative result could not contradict it. If, in 

 addition to more than one spore entering a single cell, and more than one cell 

 on a prothallus being impregnated, we have the assimilation of all the cells on 

 one and the same prothallus to contend with, the investigation seems hopeless. 

 The fortunate microscopist who shall, at the right time, succeed in a thorough 

 examination of an impregnated Fern ovum, or Fern ova, will probably see not a 

 single spermatozoid, but an ovum bristling with the tails of a crowd of these tadpole- 

 like organs (as have been seen in microscopical animal life), and thus be able to 

 explain the usefulness of large numbers of spermatozoids ; but not only this, he 

 will have established a position that but few could ever hope to attain. 



