Spermogoma and the so-called Spcriuatia. 1 1 



of resembling a flask with a bristly mouth, it comes to be 

 a cup-shaped depression on the surface of the leaf, sur- 

 rounded by a hedge of stiff bristles (Plate I. Fig. 4). The 

 function of these bristly paraphyses appears to be that of 

 preventing the exuded mass of spermatia and jelly from 

 being bodily washed off the surface of the leaf by rain. 

 This is the more necessary, because it is during wet weather, 

 as we have seen, that the spermatia, from the imbibition of 

 moisture by their investing jelly, are brought to the surface 

 of the leaf at all. The paraphyses occur with all spermo- 

 gonia except those of the Phragmidia. 



Whatever their functions may be, whether as a spore- 

 form or as spermatia properly so called, it is obvious that, 

 by being held together by a viscid substance, their chance 

 of dissemination by currents of air, etc., is but small. To 

 a certain extent their diffusion over a limited area might 

 take place in very wet weather. Rathay * has, however, 

 shown that the spermatial mass contains a certain amount 

 of some saccharine material mixed with it — a substance 

 which has the power of reducing Fehling's solution; and 

 further, that, as a matter of fact, insects do visit spermo- 

 gonia for the sake of this saccharine matter, and are thereby 

 unwittingly the agents for the distribution of the spermatia. 

 Of this latter point, he obtained actual demonstration in 

 the following manner. He had standing upon his wnndow- 

 sill some plants of Euphorbia aniygdaloidcs, upon which a 

 large number of spermogonia of EndopJiylluui cnpJiorbice 

 were in the act of exuding their contents. One day, as he 

 approached the window in question, he noticed some flies, 

 which were busy upon these leaves, fly away from the 

 leaves and alight upon the window pane. Closer scrutiny 

 showed that the flies had left their wet footmarks upon the 



* Rathay, " Untersuchungen ulicrdie Spermogonien der Rostpilze." Wicn : 

 18S2. 



