INFLUENCES AND EFFECTS. 215 
formation of mycelium or masses of toruloid cells, but in 
one or two distinct sporules were developed on the filaments 
arising from some of the larger septate spores, and in a few 
others Penicillium and Aspergillus produced their characteristic 
heads of fructification. 
With regard to the precise nature of the spores and other 
cells present in various instances little can be said, as, unless 
their development were to be carefully followed out through all 
its stages, it is impossible to refer them to their correct species 
oreven genera, The greater number of them are apparently 
referable to the old orders of fungi—Spheronemei, Melunconei, 
Torulacei, Dematiei, and Mucedines, while some probably be- 
longed to the Pucciniet and Coemacei. Amongst those belonging 
to the Torulacci, the most interesting was a representative of 
the rare genus Letraploa. Distinct green algoid cells occurred 
in some specimens. Then follow in the report details of obser- 
vations made on the rise and fall of diseases, of which diarrhcea, 
dysentery, cholera, ague, and dengue were selected and compared 
with the increase or diminution of atmospheric cells. The con- 
clusions arrived at are :— 
“Spores and other vegetable cells are constantly present in 
atmospheric dust, and usually occur in considerable numbers ; 
the majority of them are living, and capable of growth and 
development. The amount of them present in the air appears 
to be independent of conditions of velocity and direction of the 
wind, and their number is not diminished by moisture. 
“No connection can be traced between the numbers of 
bacteria, spores, &c., present in the air, and the occurrence of 
diarrhoea, dysentery, cholera, ague, or dengue, nor between the 
presence or abundance of any special form or forms of cells, and 
the prevalence of any of these diseases. 
“The amount of inorganic and amorphous particles and other 
débris suspended in the atmosphere is directly dependent on 
conditions of moisture and velocity of wind.” 
This report is accompanied by fourteen large and well-executed 
plates, each containing hundreds of figures of organic bodies col- 
lected from the air between February and September. It is valu- 
