222 — 



4 



XLIII p. 295) that both forms can be referred to the same typus, that of 

 the endogene conidia. "Zwischen beiden Sporenformen findet man alle 

 Uebergange, indem sich aus den hyalinen Sporen die dunklen grosseren 

 entwickehi konnen. Dies geschieht aber nicht immer. Nicht selten bleibt 

 die ganze Kette hyaHn, oft sieht man solche Ketten, in denen ein Teil der 

 Sporen hyahn, ein anderer dunkel ist. Manchmal fmdet das Ausreifen 

 der Sporen so rasch statt, dass man noch in der Fruchthyphe eingeschlos. 

 sene reife schwarze Sporen sieht. Die hyalinen Sporen stellen daher 

 keine besondere Sporenform dar, sondern nur ein Entwickekmgsstadium 

 der braunen, auf dem diese letzteren zuriickbleiben konnen. Die eigent- 

 lichen fertigen reifen Sporen sind die braunen". (v. Hdhnel I.e., cited 

 from Rabenhorsts Kryptogamenflora I, 8, p. 757). 



While also v. Hohnel states that "the spores properly so called" are 

 represented by the brown ones, he admits on the other hand that the hyaline 

 conidia not always are transformed into the brown ones but can remain at 

 their earlier stage of development. — As to our fungus the production 

 of the hyaline, thin-walled conidia is by far predominant and seems to 

 be a quite normal form of sporulation (indeed these conidia have thor- 

 oughly the same aspect as shows generally Chalara-spores) . It is a 

 matter of fact that the conditions under which the brown, more thick- 

 walled conidia become developed cannot be explored only preserved 

 material being at hand; the thickening, however, of the membrane points 

 towards their character of resting-spores, and not unlikely they are able 

 to help the plant through unfavourable periods. As appearing from the 

 diagnose the brown conidia can be found in the same tubuli as the 

 hyaline ones (and often presenting an intermediate aspect), quite as in 

 Thielaviopsis ; especially, however, their formation is confined to tubuli 

 near the basis of the coremium, i. e. as far localized. This fact suggests 

 — coupled with the thickening of the walls in the brown conidia — 

 that the dimorphism in this species is normal or at least being about 

 to become established. 



On decaying fruits of cacao: Las Trincheras, 25. 12. 91 (H. L.). 



i28-6-1910. 



