366 



SCIENCE 



[N. S., Vol. XL., No. 1028 



plant is on a less bulky model. On this 

 basis we may range the ferns roughly as a 

 sequence, starting from relatively bulky 

 types of the distant past, and progressing 

 to the more delicate types of the present 

 day. The large majority of the living spe- 

 cies belong naturally to the latter. But 

 the former are still represented by a few 

 genera and species which, like other sur- 

 vivals from a distant past, are frequently 

 of very restricted distribution. 



An interesting feature of the Austral- 

 asian flora is that a considerable number of 

 these relatively ancient forms are included 

 in it. Thus the Marattiaeeffi are repre- 

 sented by one species of Marattia and one 

 of Angiopteris. Though in themselves in- 

 teresting, they will be passed over without 

 special remark, as they are very widely 

 spread tropical forms. 



All the three genera of Ophioglossacese 

 are included, there being two species of 

 Ophioglossum and two of BotrycMum, 

 while HelmintJwstachys is recorded from 

 Eockingham Bay. This family is coming 

 more than ever to the front in our compari- 

 sons, owing to their similarity in various 

 aspects to the ancient Botryopterideas. 

 Though the Ophioglossaeese have no secure 

 or consecutive fossil history, still they may 

 now be accepted as being very primitive 

 but curiously specialized ferns. Perhaps 

 the most interesting point recently detected 

 in them is the suspensor found by Dr. 

 Lyon in Botrychium obliquum, and by Dr. 

 Lang in Helminthostachys. This provides 

 a point for their comparison with the simi- 

 lar embryonic condition in Danoea, as dem- 

 onstrated by Professor Campbell. The ex- 

 istence of a filamentous initial stage of the 

 embryo is thus shown for three of the most 

 primitive of living ferns. Its existence in 

 all of the Bryophytes, and in most of the 

 Lycopods, as well as in the seed-plants, is 

 a very significant fact. Dr. Lang suggests 



that "the suspensor represents the last 

 trace of the filamentous juvenile stage in 

 the development of the plant, and may have 

 persisted in the seed-plants from their 

 fiHcineous ancestry." Such a possibility 

 would fit singularly well with the theory of 

 encapsulation of the sporophyte in the 

 venter of the archegonium. 



The representation of the ancient family 

 of the Osmundacese in the Australasian 

 flora is very fine, though limited to five liv- 

 ing species, while Osmunda itself is absent. 

 It is, however, interesting that the family 

 dates back locally to early fossil times. It 

 was upon two specimens of Osmundites 

 from the Jurassic rocks in the Otago dis- 

 trict of New Zealand that the series of re- 

 markable papers on "The Fossil Osmun- 

 daceas" by Kidston and Gwynne-Vaughan 

 was initiated. It is no exaggeration to say 

 that these papers have done more than any 

 other recent researches to promote a true 

 understanding not only of the Osmundacese 

 themselves, but of fern-anatomy as a whole. 

 They have placed the stellar theory in ferns 

 for the first time upon a basis of compari- 

 son, checked by reference to stratigraphical 

 sequence. It would be leading us too far 

 for me to attempt here to summarize the 

 important results which have sprung from 

 the study of those fossils, so generously 

 placed by Mr. Dunlop in the hands of those 

 exceptionally able to turn them to account. 

 It must suffice to say that it is now pos- 

 sible to trace as a fairly continuous story 

 the steps leading from the protostelic state 

 to the complex condition of the modern Os- 

 munda. These facts and conclusions are to 

 be put in relation with the anatomical data 

 fast accumulating from the Ophioglossaceffi 

 in the hands of Professor Lang and others. 

 From such comparisons a rational explana- 

 tion of the evolutionary steps leading to the 

 complex stellar state in ferns at large be- 

 gins to emerge. This is no mere tissue of 



