132 CURREY, ON FUNGI. 



the sporidia of Puccinia are always distinguishable from those 

 of Phragmidium by their reniform shape, and that the germ- 

 filament of the upper cell of Puccinia always makes its way 

 out through the apex of the fruit ; but I have seen Puccmia 

 graminis produce globular sporidia as shown in fig. 21, and 

 I have seen the germ-filament of the upper cell of Puccinia 

 Lychnideai'um make its way out at the side of the upper cell, 

 as shown in fig. 22, instead of through its apex. 



The germination of Triphragmium is described by Tulasne 

 as precisely similar to that of Phragmidium, but in the only 

 instance in which I have succeeded in prociu'ing germination in 

 the former plant it took place in a manner somewhat different, 

 and which I have di'awn in fig. 23. The filament grew to a 

 considerable length, and formed four septa at its extremity ; 

 no sterigmata or sporidia were produced, but the orange- 

 coloured endochrome became accumulated in each of the 

 four terminal cells in the form of two globular masses, as 

 shown in fig. 23. One of the four terminal oblong joints 

 fell off, and commenced germination, as shown in fig. 24, 

 and it was obvious that the remaining three joints were on 

 the point of becoming separated from one another. 



In illustration of the gradation from the fruit of Uredo 

 to that of Phragmidium, and of the close resemblance be- 

 tween Phragmidium and its allied genera, I would here call 

 attention to figs. 25 to 33 ; they all represent different forms 

 which I found in the fruit of the same specimens of PJiragmi- 

 dium potentiUa. Fig. 25 represents the normal form of the 

 Uredo ; figs. 26 and 27 show the commencement of the 

 formation of a di^dsion Avhich becomes complete in fig. 28. 

 Fig. 29 is quite undistinguishable from an Uromyces, as is 

 fig. 30 from a Puccinia, and figs. 31 and 32 might well be 

 taken for fruits of Triphragmium, and if seen apart from the 

 others could not be named with certainty. Although the 

 fruit of Triphragmium has usually only three divisions, it is 

 by no means uncommon to find four. Fig. 33 shows the 

 perfect normal form of fruit of this species of Phragmidium. 

 In the fruits represented by figs. 25 to 28 the colour was 

 the bright orange of the Uredo ; in the rest, the colour was 

 the usual dark brown of the Phragmidium. I may here 

 observe that the spines or prominences seen in the Uredincs 

 which accompany the Puccinise, and which have been ad- 

 vanced as a mark of distinction between the two kinds of 

 fruit, exist, I believe, only on the surface of the endosporium. 

 I have frequently noticed that these Uredo grains, although 

 at first sight truly echinulate, are svirrounded on the exterior 

 by an extremely delicate and perfectly smooth membrane. 



