FERNS, APOSPOROUS AND APOGAMOUS. 243 



normal form to reproduce itself in both ways, and since his 

 asexual examples occurred in thickly-sown pots, it would 

 appear to be due to some extent to a starved condition 

 induced by overcrowding, which checks the formation of 

 the archegonia, and leads to the simple budding in their 

 place. In all these instances the young plants are en- 

 gendered upon precisely the same spots on the prothallus 

 as the sexual one would occupy, and as their development 

 and appearance are identical, it is only by preliminary 

 watching that their apogamic origin can be determined. 



A case of Apogamy (or rather two cases), however, 

 recently occurred in a sowing of my own, which is quite 

 distinct from any I have seen described. A sowing of a 

 plumose variety of Athyrium jilix foemina failed almost 

 entirely, only two or three prothalli surviving. One of 

 these after growing very large, nearly half an inch across, 

 remained perfectly dormant the whole of the summer ; 

 early in the autumn, however, the edge of the prothallus 

 began to grow out and upwards in two places, and eventu- 

 ally two slightly curved horns, 1 each about one quarter 

 inch long, developed perpendicularly, one on each side of 

 the indentation or sinus common to most prothalli. Later 

 on, at a short distance from each tip, a small whitish bulbil 

 appeared and these increased in size until the circination of 

 several fronds was plainly visible, a small crown or caudex 

 being developed. No roots, however, were emitted, and 

 the two little plants, both, be it remarked, identically 

 situated and very like in form, were evidently supported by 

 the prothallic root-hairs, though by this time most of the 

 prothallus was brown and dead. Subsequently I placed a 

 piece of loam in contact, and into this both plants rooted 

 and fronds were sent up, the first of which had no less than 

 ten pinnate divisions on either side. It was thus, it will be 

 seen, very different from the usually simple primary fronds 

 produced either sexually or apogamously heretofore. Later 

 on still, noticing that the tips of the horns were showing 

 signs of dilating, I cut these off with a razor and laid them 



1 Gard. Chronicle, 10th Nov., 1894. 

 17 



