:;| AMPHISPORES 



Amphispores. 



In countries which are arid or Mini-arid, there is found in 

 certain species a form <>f uredospore which has led to several 

 mistakes owing to its misleading appearance. The spores are 



provided with a thick cell-wall or have the summit thickened 

 conically, after the style of many a teleutospore of Uromyces, 

 and are supported on a persistent pedicel, so that one would 

 not take them for uredospores; nevertheless they will be found 

 to have more than one germ-pore and to germinate by a germ- 

 tube, although only after a period of rest. These were named 

 by Carleton amphispores : they were first discovered in Pnccinia 

 renins. They are evidently ;i provision to enable the spore to 

 pass through an unfavourable period unharmed, and reinfect a 

 hosi of the same species when occasion arises. The amphi- 

 spores of Pnccinia atrofusca Holway, though echinulate and 

 possessing two equatorial germ-pores, were first described by 

 the discoverers. Dudley and Thompson, as the teleutospores of 

 a Uromyces, and the same thing has happened in other cases, 

 e.g. Puccinia convolvuli, P. tosta, and P. cryptandri. The 



nearest approach to amphispores found in 

 British species is in P. Pruni-spinosae (Fig. 

 22), in which the}' have been mistaken for 

 paraphyses and were so figured in a well- 

 known text-book. There is another kind of 

 spore, presently to be described, called a 



■Fig. 22. Amplnspore raesuspore, which bears a superficial resem- 

 of Puccinia Pruiii- * A . . 



spinosae. x600. blance to an amplnspore. It is a mistake to 



call amphispores a transition- form between 



uredo- and teleutospores, since they are of later evolution than 



the two latter. 



Teleutospores. 



The meaning of the word teleutospore is end-spore ; it was 

 considered to represent the stage when growth was ceasing for 

 the season. This is not the case, however, in all species, and 

 the word must now be used with another connotation, viz. a 

 teleutospore is one which germinates by the production of a 

 basidium and basidiospores. 



