GERMINATION AND GROWTH. 147 



taming a brownish protoplasm, on which four spicules, bearing 

 as many sporules, are generated. 



The germination of the black fruits of Phragmidium only ap- 

 pears to take place in the spring. It greatly resembles that in 

 Puccinia, except that the filament is shorter, and the sporules 

 are spherical and orange-coloured, instead of being kidney- 

 shaped and pale. In the species found on the leaves of the 

 common bramble, the filament emitted by each cell attains three 

 or four times the length of the fruit. The 

 granular orange protoplasm which fills it 

 passes ere long into the sporules, which 

 are engendered at the extremity of pointed 

 spicules. After the long warty fruits are 

 emptied of their contents they still seem 

 as dark as before, but the pores which are 

 pierced in the sides, through which the 

 germinating filaments have proceeded, are 

 more distinctly visible. 



It will be observed that throughout all 

 these allied genera of Uromyces, Puccinia, 

 Triphragmium, and Phragmidium the same 

 type of germination prevails, which confirms 

 the accuracy of their classification together, 

 and renders still less probable the sup- 

 posed affinity of Phragmidium with Spori- 

 desmium. which was at one time held by 



, . , , , . , . FIG. 87. Germinating 



very astute mycologists, but which is now pseudospore of Phragmi- 

 abandoned. This study of germination dium buibosum. (Tuiasne.) 

 leads also to a very definite conclusion with regard to the genus 

 Uromyces that it is much more closely related to Puccinia and 

 its immediate allies than to other unicellular Uredines. 



The germination of the pseudospores of the gelatinous Ure- 

 dines of the genus Podisoma was studied by Tuiasne.* These 



* Mr. Berkeley has lately published a species under the name of P. Ellisii, 

 in which the gelatinous element is scarcely discernible till the plant is moistened. 

 There are two septa in this species, and another species or form has lately been 

 received from Mr. Ellis which has much shorter pedicels, and resembles more 



