67 



the under surface upward instead of the upper ; and as the 

 latter is better adapted to receive the Hght, a compromise, 

 as it were, results in the twist in question. It is curious 

 that a natural sport of this description should really be in 

 conflict with the law that a leaf or its equivalent is so 

 arranged as to catch directly as much light as the environ- 

 ment permits. In that very peculiar tree, Liriodendvon 

 tidipifenim, or the Tulip Tree, the broad leaves are peculiar 

 in terminating squarely, the midrib slightly projectmg as a 

 thorn, and it is a very curious fact that while this, w^e 

 believe, has no parallel in flowering plants, at any rate, as 

 being a constant specific character, several of our native 

 fern species present precisely the same feature in wild 

 varietal forms — viz. the Hartstongue, Lady Fern, Lastrea 

 filix-mas, L. inontana — and we have also received the same 

 type of variation from the United States in PoJypodinm 

 hexagonopteruin tnmcatum. In all these the unrolling frond 

 or fern division suddenly ceases to develop the leafy portion 

 on each side of the midrib, though that continues for a 

 short distance as a bristle or thorn-like point. 



Chas. T. Druery, V.M.H., F.L.S. 



INDUCED APOSPORY IN FERNS. 



By favour of the Gardeners' Chronicle, I give the following parti- 

 culars of a discovery regarding the reproductive faculty of 

 Ferns in general, which should interest the readers of the 

 Gazette. So far as I know, this had not appeared in a form 

 adapted to English readers until by pure chance I came across 

 Professor Goebel's paper in a secondhand bookseller's list, and 

 at once obtained a copy on the strength of the title, upon 

 which I framed the article for the Chronicle now reproduced. 



Since the first discovery of apospory by the present 

 writer in 1884, i^ ^^^ been found that this phenomenon, 

 namely, the production of prothalli direct from the frond, 



