BETTS : THE FUNGI OF THE BEE-HIVE. 151 
length (15-16 m in the form with small conidia). In both the 
conidiophore-stalk is about 5 » in diameter. 
The colour of the vegetation is very similar in both forms, but 
there seems to be a slight tendency for the form with smaller conidia 
to produce a paler, greyer, or more bluish-green vegetation than that 
of the other. 
Only the conidia appear able to resist the action of sulphuric 
acid when heat is applied. No particular effect is produced by 
hydrochloric acid or caustic potash solution. 
Fig. 18.—Penicillium crustaceum. Conidiophore and conidia (2°5-3p). x 1,400. 
This species seems to dislike high temperatures; in one case a 
culture of the form with larger conidia germinated and flourished at 
26°-38° C., while the form with small conidia in a similar tube did 
not germinate and appeared to have been killed; but as a rule, 
cultures exposed to high temperatures failed to germinate even when 
transferred to room temperature. At room temperature and under 
outdoor conditions the fungus did well. 
Gelatine is not liquefied. In some cases litmus media were 
reddened, but the production of acid is evidently not so great as in 
the case of Citromyces glaber. The vegetation on bouillon agar 
was grey instead of green. 
