BETTS : THE FUNGI OF THE BEE-HIVE. 155 
diameter; the smaller ones average about 60-65 uw. The azygospores. 
are generally unequally developed, one of the pair being often 
aborted ; they are 60-70 » in diameter when well developed. 
The zygospores have not been germinated, neither has it been 
as yet determined whether this species is homo- or heterothallic. 
On heating in sulphuric acid all parts of the fungus are dis- 
solved, excepting the exospore of the zygo- and azygospores. 
Similar treatment with hydrochloric acid is survived also by the 
spores and hyphae, sometimes by the columellae (but these last are 
rendered very brittle). Caustic potash does not produce any marked 
immediate effect on any parts. 
This species dislikes high temperatures; the spores appear to be 
killed by exposure to 269-389 C. At room temperature and out-of- 
doors the fungus does well. 
Growth was luxuriant on most media; on potato and bread, as 
stated, zvgospores are produced The fungus would not grow on 
pollen, and in most cases grew poorly on honey media; it did not 
flourish on pollen decoction gelatine or on apple. Gelatine is lique- 
fied, and the resulting liquid is often coloured a tawny yellow (about 
the colour of Flemming’s fluid). A culture on bouillon agar was also 
coloured yellow. Acid is probably not produced. 
The description here given agrees in most points with that given 
by Fischer for Mucor erectus (10, p. 197)... The principal difference 
is that Fischer describes the spores as uniform in shape (‘‘ gleichge- 
staltet ’’), whereas in my specimens there is a decided tendency to 
variableness in the form of the spores. He also gives the zygospore 
diameter as 40-65 ». Otherwise the agreement is close. 
Fischer mentions echinulate gemmae, which did not occur in 
my cultures; also a spherical yeast-form. This latter, it is believed, 
was met with occasionally in the earlier course of the research; but 
has not been observed lately. 
Pericystis alvei, Betts. 
This species is apparently a true bee-hive fungus, occurring 
only on the pollen stored in the combs, and adapted to life in the 
hive. The appearance, both of the mycelium (Fig. 23), and of the 
dark-green cysts (Fig. 24) containing numerous sperical spores (Fig. 
25), is very characteristic and peculiar, and makes the identification 
of the fungus an easy matter. The process of development of the 
1The dimensions given by Fischer for M, erectus are greater than those in Bainier’s 
original description (see 70, p. 197). 
