TRICHOPHYTON 



997 



Fig. 502. — Trichophyton citrrii, to show 

 Ladder-like Rows of Mycelial Spores. 



On this medium the growth of the various Trichophytons is much 

 less abundant than on sugar media, but the cultures are fairly 

 characteristic, and do not become pleomorphic. 



Experimental Inoculations. — Certain Trichophytons can be easily 

 inoculated experimentally into man and many of tlic laboratory 

 animals — guinea-pigs, rab- 

 bits, etc. Sabouraud advises 

 the inoculation of portions 

 of the cultures to be made 

 into a small flictena, arti- 

 ficially induced by burning, 

 such as by applying to the 

 skin a lighted match. 



The intravenous injection may induce generalized lesions of 

 the internal organs. 



The intraperitoneal injection as done by Citron may induce a 

 type of peritoneal pseudo-tuberculosis. 



Mode of Infection. — Infection may take place from man to man — 

 this is generally the case with Trichophytons of the group endothrix — 

 or from the lower animals to 

 man. There is also little doubt 

 that Trichophytons may live 

 saprophytically in nature, this 

 explaining sporadic cases of 

 trichophytoses in man. 



-mm 



Fig. 503. — Trichophyton currii, 

 Four Days' Growth on Sabou- 

 raud's Maltose Agar at 34° C, 

 TO SHOW White Growth with 

 Knob-like Centre. 



Fig. 504. — Trichophyton violaceum 

 VAR, khartoumense. 



(Note absence of acuminate centre 

 and dark [violet] colour of the 

 growth.) 



Reproduction. — This takes place by— 



1. Lateral and terminal conidia, supported by short sterig- 

 mata. 



2. Chlamydospores ; these are rare. 



3. Large terminal septate and unseptate spindles. 

 Classification. — -The principal species of the genus Trichophyton 



arranged chronologically are : — 



