INDUCED APOGAMY 



140 should be 280, this number may be thought of as octoploid if the normal plant is a 

 tetraploid. Unfortunately the only specimen died as a result of attempted transfer 

 from Manchester to Leeds and nothing more can be said about it. It would be a matter 

 of some interest to repeat the induction of such a plant in order to determine whether or 

 not it would be capable of becoming fertile. It would be expected to show marked signs 

 of abnormality and of sterihty if the grade of polyploidy imputed to it is genuine. 



With Scolopendrium as with Doodia I am fortunate in having had access, through the 

 vigilance and private enterprise of Mr Ashby, to residual material remaining in culture 

 from an earlier investigation, the material in this case being that relating to Lang's 

 second paper (1929) on 'apogamy and the production of sporangia on prothalH in 



Fig. 207. Meiosis (early diakinesis) in normal Doodia caudata (Cav.) R.Br, 

 to show regular pairing, permanent acetocarmine. x 1000. 



Scolopendrium'. The strain of Scolopendrium used had originated as a stray spore of 

 unknown origin which had germinated in the moss house in Manchester University 

 Experimental Grounds and given rise to a plant with characteristic, heritable, leaf ab- 

 normalities of the type so often seen in horticultural strains. The leaf morphology, which 

 can to some extent be seen in Fig. 208, could have been described as 'ramo-furcate', and 

 in addition to the forking of the rachis and profuse branching of the leaf apex, there was 

 a tendency to produce sori on the upper as well as on the lower surface of the leaves. The 

 prothalli obtained from spores of this plant also showed a somewhat comparable pecu- 

 liarity in the frequent production of archegonia on both surfaces, but they were other- 

 wise quite normal and readily gave rise, when suitably watered, to crops of young plants 

 with a morphology exactly similar to that of the original specimen. The morphological 

 characteristics of both generations therefore appeared to be genetically determined. 

 When water was withheld, in the manner already described, the unfertilized prothalH 

 became very large and more abnormal in appearance. One sign of incipient apogamy 



204 



