1899J MICROSCOPICAL JOURNAL. 73 



when the Euphorbia dies down, the mycelium hibernates 

 in the rhizome. 



The spermogonia are generally formed below the up- 

 per surface of the leaf bearing the secidia, and are devel- 

 oped from the same mycelium. Sometimes, however, 

 they occur on the lower surface, and in juxtaposition with 

 the Eecidia. These flask-like growths in the sub-cortical 

 tissue, with brushes of hair-like filaments at their pro- 

 jecting apices, pour out at maturity vast numbers of 

 spermatia — extremely minute bodies resembling spores — 

 which have been held by some to be the male sexual ele- 

 ment. There seems, however, to be a consensus of opin- 

 ion, amongst f ungologists, that there is not sufficient war- 

 rant for this idea. The spermatia are associated with a 

 viscid fluid. The largest examined are only the 1-2500 of 

 an inch in length and the 1-100,000 of an inch in width. 

 Their function is not known ; but it is difficult to believe 

 that they have none, useless indeed they are merely a 

 survival of structures which were useful under conditions 

 that have long since passed away. This is probably true 

 in most instances, but spermatia of some species have 

 been caused to germinate and produce a mycelium like 

 that of the uredo condition of the fungus. Sometimes 

 the spermogonia occur in conjunction with the uredo- 

 spores, and sometimes in conjunction with the teleuto- 

 spores, though this latter is apparently not the case in 

 the genus Uromyces. 



The secidiospores are produced in basipetal chains, the 

 oldest spores being at the apex of the chain, the young- 

 est at the base : they are 1-1,250 of an inch in diameter. 

 As the terminal spores mature they become free and form 

 an orange powder, which fills the whitish-edged and 

 slightly fringed cluster-cup. They are, at maturity, 

 globular or polygonal, and roughened on the outer sur- 

 face. The walls are thinner in certain places, and it is 

 through these so-called germ-pores — and as a rule from 



