THE GENUS PENICILLIUM. 



329 



structure of the conidiophores belonging to the same species. 

 This method of branching produces the characteristic brush shape 

 of the conidiophores. The sterigmata usually diverge in a very 

 appreciable manner, and vary in number from two to ten, their 

 relative length (referred to the head) and pointed shape varying 



FIG. 177. Conidia of various species of Penicilliuin, all drawn to the 

 same scale. (Mag'u. about 1200). 



I. P. Camembert (conidia 3.1-4.5 M in diameter) ; 2. P. brevicaule (7-10^ by 5.7-6.8 M) : 

 3. P. purpuroo-enum (2.8-3.3 M b 7 2 M) ; 4. P. claviforme (3 /. by 2 /u) ; 5. P. 

 rubrum (2.8-3. 5 u in diameter) ; 6. P. italicum (4-5 M by 2-3 n) ; 7. P. olivaceum 

 (6-10 n by 4-6 M) ; 8. P. luteuin (2.3-3 f* b 7 14-2 M) ; 9. P. glaucuin (2.5-3 M in 

 diameter. 



Measured ou growths from pure cultures on wort g-elatin. (Original.) 



with the species, but being generally constant in one and the 

 same species. The conidia of the commoner species (" P. glaucum" 

 P. iuteum, P. italicuni) are globular to ellipsoidal, mostly gla- 

 brous, thin-walled, and almost colourless when taken singly, but 



