MORPHOLOGY IN CULTURE 



149 



arise. The protoplasm in these conidiophores condenses or accumu- 

 lates at intervals and septa are formed. A typical conidiophore then 

 resembles a chain of spores separated from each other by spaces 

 devoid of protoplasm. Frequently the original septum can be ob- 

 served midway of the space separating two spores, indicating a con- 

 densation of the protoplasm to form the spore. These spores are 

 usually called chlamydospores and they resemble chlamydospores 

 except in their relationship to spe- 



.-^yr 





/ 



\ 





cialized hyphal branches. As the 

 culture ages similar spores form in 

 many of the aerial hyphae with- 

 out any apparent specialization 

 and the designation of chlamydo- 

 spore seems to be justified. These 

 chlamydospores are highly infec- 

 tious and their accidental inhala- 

 tion by laboratory personnel who 

 handle cultures has resulted in 

 many infections. Spores of this 

 type are formed in large numbers 

 when the fungus grows saprophyti- 

 cally on either natural or artificial 

 substrates and it is supposed that 

 they are present in -^ind-blown 

 dust and initiate infection when 

 contaminated air is inhaled. They 

 have not actually been found in 



air, and although they have been isolated in culture from soil the 

 actual gi'oui;h of the fungus in soil has not been demonstrated except 

 in the laboratory. 



When chlamydospores from a culture are injected intraperito- 

 neally into a laboratory animal each spore is capable of rounding up 

 and growing directly into a sporangium as previously described. The 

 spores may remain in short chains during at least the early stages 

 of development in experimentally infected animals, thus gi^'ing rise 

 to a chain of sporangia. Unless one realizes the origin of these chains 

 they may cause confusion, especially when only two sporangia are 

 connected by a short empty cell, thus bearing a superficial resem- 

 blance to conjugating cells. Closely appressed sporangiospores of 

 the parasitic growth phase may also remain adjacent after dissemi- 

 nation from the ruptured sporangium and give a false appearance of 

 budding. 



Fig. 76. Chlamydospores In a young 



culture of Coccidioides immitis. From 



C. W. Emmons, M ycologia, 34, 460 



(1942) 



