243 



Assuming the truth of the recapitulation theory (i.e., that 

 ontogeny is an epitome of phylogeny), this would seem to 

 suggest that apospory is an atavic trait in ferns — a character 

 which may have been general or even universal in the infancy 

 of the race. This idea is also borne out to some extent by 

 the fact that apospory is favoured by a uniformly humid 

 atmosphere, a condition which probably prevailed in early 

 geologic (say, Silurian and Devonian) times. 



(6) The prima facie unlikeliness of A. Filix-foemina var. 

 unco-glomeratum as a subject for apospory leads me to 

 suspect that that phenomenon could be induced in many — 

 possibly in most — ferns by taking sufficient trouble. This 

 fern has apparently nothing in common with the other 

 abnormal forms which have manifested apospory. All 

 these, so far as I know, belong to the plumose or ultra- 

 plumose sections of varieties. It is true that among them 

 are two other crested ferns, viz., Cropper's Lastrea paleacea 

 var. cristata pxdcherrima and Scolopendrium var. crispum 

 Drummondice ; but both these are specially modified forms, 

 whose appearance at once suggests to the experienced eye 

 that they are likely subjects for apospory. It is evident 

 that there is a wide field for further experiments in the 

 cultural inducement of apospory. Some of these further 

 experiments I hope to make and to record results in due 

 time. 



Note. — On December 18, 1898, I took up one of the 

 original prothalli which had not yet produced either frond 

 or bud, shaved off the root-hairs, and examined it with the 

 microscope for archegonia and antheridia. I found the 

 " cushion " crowded with archegonia, in some of which the 

 egg-cell could be distinctly seen. A few antheridia were 

 found in the usual situation, but they were apparently not 

 yet mature. 



