entomophthorp:ae of the united states. 145 



which bi-;inch and elongate, growing constantly more attenuated, their protoplasmic con- 

 tents becoming separated by successive cross partitions from the empty hyphae left behind 

 (iig. 240) . It ma}^ here be mentioned that this separation by cross partitions is common 

 in the general growth of the fungus. The hyphae produced thus from eonidia have the 

 usual characteristics: agranular protoplasmic contents Avhich often shows a very notice- 

 able streaming motion, and contains large oil globules and a hyaline wall. The power 

 of germination lasts, according to Brefeld, at most only a week, or slightly more in 

 E. radicans {^E. si^haerosperma) ; but in my own experience I have found the period 

 usually much shoi'tei- than this. The ])eriod is in all probability very variable; spores 

 that have been formed under unfavorable conditions being better able to withstand simi- 

 lar conditions: the endurance of the spores, moreover, varies with different species. As a 

 rule, gei-mination takes place very soon after dischai-ge, and if the conidium has neither 

 fallen upon a proper host nor upon a wet surface it proceeds to form 



Secondary eonidia. — The secondary conidimn is a provision foi- further dissemination 

 in case the primary spore has fallen on a sul)stance unsuited to its proper development. 

 The most common method of formation consists in the production of a hypha of vari- 

 able length, which, growing vertically upwards, becomes swollen at its extremity into a 

 basidium, and produces a conidium similai- to that whence it is derived. This is dis- 

 chai'ged in the usual fashion, and may in tnrn ])roduce tertiar3% etc., eonidia, in a similar 

 way, until its vitality is exhausted or it has found a suitable lodgment. The conidio- 

 phore formed in this process is usually simiile, even if the ty^De from which it was de- 

 rived is digitate ; yet I have seen, in a case where numerous spores had been discharged 

 upon Avet moss, that the h^'phae arising from them united to form a mass of conidio- 

 ph(jres of the digitate type peculiar to the species. 



Although the form of secondary conidium just described is most commonly found, 

 and is apparently the normal type in all species under favorable conditions, it is subject 

 to several interesting vaiiations that are dependent, for the most part, upon an insufficient 

 supply of moisture. The first of these consists in the production of a secondary conid- 

 ium quite diffei-ent from the ])rimary, either by direct budding from it (fig. 9), or borne 

 upon a short hypha of germination (fig. 362). These eonidia are also discharged; but 

 are apparently better suited to resist unfavorable conditions than the ordinary ones, and 

 proba])ly retain their poAver of germination much longer. The most singular modifica- 

 tion, hoAvever, is presented by a fcAV species allied to E. sjihaerosjjerma and E. Eresenii. 

 In these forms and their allies, Avhen the conditions of moisture are unfavorable for the 

 ordinary process, a long, slender, capillary conidioi)hore is jjroduced, on the end of which 

 is borne a peculiar secondary conidium differing still more Avidely from the parent spore 

 than in the case just mentioned. 



These secondary eonidia (figs. 157, 191, etc.) are, Avith one exception, nearly almond- 

 shaped, with noticeably thick Avails, and are not discharged. Whether they ever produce 

 tertiary spores similar to the primary ones, I have been unable to determine; but the for- 

 mation from them of tertiary eonidia similar to themselves is not uncommon. They nuiy 

 often be seen genniuating l)y means of an irregulai- hypha Avhieh, beginning as a drop- 

 like protuberance from the apex of the spore (fig. 119), may grow to a considerable 

 length (fig. 122). Eidam, in his paper on Basidioholus (PI. 9, fig. IG), figures a mode 



