ME. F. O. BOWEE OK ABOSPOBY IN FEUNS. 



3G7 



not only of the sporangium and spores, but also of the whole 

 oophore generation. This may be represented graphically thus :— 



Diag. 6. 



JProtkallus 



Isoefe# Plant 

 orSporoplwrv 



It is clear that iu many points this most interesting process 

 of aposporous reproduction in the Ferns requires further inves- 

 tigation. It is confidently hoped that the cultures now pro- 

 gressing in Kew, and in the private collections of Mr. Druery 

 and others, will clear up many uncertain points. It may also 

 be expected that, since attention is now called to the subject, 

 other examples of the same or similar phenomena may be dis- 

 covered which had hitherto escaped notice. 



DESCRIPTION OP THE PLATES. 



Plate XL 



Athyrium Filix-foemina, var. clarissima. 



Fig. 1. An arrested sporangium with annulus already formed, but the cell-walls 

 not thickened ; the cells of the head of the sporangium bare almost 

 lost their contents, while those of the stalk (st) have abundant proto- 

 plasm and chlorophyll-granules. x325. 



Pig- 2. An arrested sporangium, of which the archespore (a) has not undergone 

 division The stalk (st) is abnormally enlarged, and its cells have 

 abundant protoplasm and chlorophyll. X325. 



Pig. 3. A sporangium, similar to tig. 2, after cultivation on moist soil for seven 

 days. The shaded head of the sporangium does not grow, but active 

 cell-division and growth has gone on in the stalk (st). X 325. 



Pig. 4. A similar sporangium with rather more enlarged head, showing super- 

 ficial cells. X325. 



Fig. 5. A similar sporangium, showing irregular growth in the stalk. x325. 



Pig. 6. A sporangium after continued cultivation for twelve days; the stalk is 

 much enlarged, and growtb, with a wedge-sliapcd apical cell, has 

 begun laterally from it. X 13). 



