931 



transcript of Suminski's views, premising however that we omit 

 entirely his detailed account of the germination of the sporules of 

 Pteris serrulata, on which he informs us all his observations have been 

 made, because his descriptions do not differ sufficiently from those of 

 Henderson, above cited, to render them of general interest, or of im- 

 portance in the present inquiry. 



" On placing the pro-embryo of a fern under the microscope, cer- 

 tain gland-like, globular cells will be seen projecting from its under 

 surface, and occasionally, but not so commonly, from its margin. As 

 the pro-embryo advances towards maturity, these bodies increase in 

 number, and principally occupy that basal portion of the under surface 

 from whence the rootlets may be observed to issue. Some species of 

 ferns, and especially Pteris serrulata, are remarkable for the great 

 number of these bodies. These globular protuberances originate in a 

 sack-like elongation of particular cells of the pro-embryo, but a free 

 cell is soon formed in their interior containing a homogeneous muci- 

 lage, and within this, transparent globules or distinct nuclei with 

 nucleoli. As soon as this interior cell has so far increased in size as to 

 fill the original projecting sac, it is divided by a septum from the sur- 

 face of the pro-embryo, and thus attains the character of an indepen- 

 dent organ. A third cell is often formed beneath this septum, and 

 being flattened above and below, serves as a support to the upper 

 cell, which frequently, at a very early period of its existence, displays 

 in its interior new and very minute cellules, filled with a granular 

 substance ; these are various in number, but are often arranged with 

 great regularity ; they gradually become more distinct, at last filling 

 up the parent cell, which has the appearance of a sac distended with 

 granules, the granules themselves from mutual pressure receiving a 

 parenchymatous appearance. When the parent cell has attained ma- 

 turity, it bursts open at the top, and discharges a number of small 

 round bodies enveloped in mucilage. I have observed in some cases 

 a rythmical motion uniformly pervading the whole of the discharged 

 mass : the discharged bodies very shortly after their escape from the 

 parent cell usually exhibit a rotatory motion on their own axes; each 

 of them unfolds a spiral filament, which however remains attached to 

 the delicate cellule [in which it was contained], and performs a rapid 

 revolution round its axis. 



" As Nageli has described with great accuracy the various motions 

 of these spiral filaments, it appears to me unnecessary in this place 

 to reiterate his observations : I must, however, remark that I have 

 discovered on the clavate anterior extremity of the spiral filament very 



