ON Al'OSPORY i:S POLYSTICHUM ANGUlARE. 437 



et Thunbergii U. alpini et JF. macranthi unos et eosdein descripsit, 

 quamobrem Miquclianum specimen (non Thunbergianum) U. al- 

 pini (nt nominatur) esse re vera -E. macranthi^ Morr. et Dccne., 

 est sumendum. 



EXPLIOATIO TABULA XXI. 



Achlys triphylla, DC, xav^jajponica, T. Ito. 



Fig. 1. Specimen subdeflorens, mag. nat. 



2. Spicae pars cum carpcllis iiumaturis, mag. auct. 



3. Flos subdefloratus cum 3 stamiuibus pcrsistcntibus, mag. auct 



4. Stamen, mag. auct. 



On a new Instance of Apospory iu PolysticJiiim ctiijnlare^ var. 

 pnlcherrimum^ Wills. By Charles T. Druert, F.L.S. 



[Eead IGlb December, 188G.] 



In December 1884, and previously, I brought before the notice 

 of this Society the results of certain investigations into a mode 

 of reproduction in Athyrium Filix-fwmina^ var. clarissimnj 

 hitherto unobserved, and to which Prof F. O. Bower gave tlie 

 name of apospory, the spore being eliminated from the life-cycle 

 of the fern, the prothalli springing direct from the stalks of 

 aborted sporangia. This discovery in the variety o^ Athyrium in 

 question was followed by Mr. Gr. B. Wollaston's discovery of a 

 kindred phenomenon in an abnormal form oi FolysHclium angu- 

 lare^ var. pulcherrimum, Padley, in which plant, however, it is 

 developed in an altogether different manner, the prothalli being 

 produced in this case by simple extension and dilatation of the 

 growing tips of the pinnules, so that not only the spore, but the 

 entire sorus is excluded from the normal cycle of existence. 



The particular specimen of Polystichum angulare in which this 

 phenomenon w^as remarked was found many years previously, 

 growing wild in North Devon, since which time it had constantly 

 produced its characteristic expansions of the pinnule-tips, which, 

 however, were regarded at first as a minute form of that cresting 

 common to so many abnormal forms of Ferns, and consequently 

 their true character as prothalli proper remained for a long time 

 unsuspected. 



One of the peculiar characteristics of this Fern is a marked 

 elongation of all the lower divisions of the 2)innai, i, e. pinnules, the 

 upper ones retaining nearly or quite their normal outline ; and 



