V. H. Blackman. 
o 
frond, of the Sphenopteris type, is shown in superficial section, but 
there is no evidence to connect it with our sporangium. However 
this may be, it is a distinct point gained, to know that this form of 
sporangium, at any rate, was that of a true Fern. 
In conclusion I desire to express my thanks for help given by 
my wife, who was the first to notice the germinating spores, and by 
Mr. L. A. Boodle F.L.S., who has taken much kind trouble in 
preparing the illustrations. 
ON THE FERTILISATION, ALTERNATION OF GENERA¬ 
TIONS AND GENERAL CYTOLOGY OF THE UREDINETL 
By Vernon H. Blackman, M.A. 
(Preliminary Notice). 
HE question of the sexuality of the Uredineae has been a 
disputed one ever since the suggestion put forward by Meyen 
more than sixty years ago that the spermogonia and aecidia represented 
male and female organs respectively. Further observations on 
the usual close association of these structures and the apparent 
absence of power of germination of the spermatia seemed at first 
to confirm this view ; still later investigations, however, failed to 
trace a process of fertilisation or even to discover any clear evidence 
of sexual organs in the aecidia. Such results, combined with the 
observation that the spermatia were under certain conditions 
capable of germination to a slight degree, led Brefeld to put for¬ 
ward the view, accepted by many botanists, that sexual organs were 
wanting in the Uredineae and that the spermatia were nothing more 
than conidia. A great objection to this view, however, was the fact 
that the spermatia seemed quite incapable of causing infection, and 
germinated feebly only under conditions (highly artificial for true 
parasites like the Uredineae) of nutritive solutions. 
The cytological observations of Poirault and Raciborski and of 
Sapin-Trouffy about 1896 threw very little light on the spermatia, the 
