272 THE EVOLUTION OF LIFE 
_ After these two samples of the sediment had been 
abstracted with a sterilised pipette, the tube was 
again closed and put away in a box (at the ordinary 
temperature of the air) for another eleven weeks.! 
When opened on November 12th the fluid was found 
to be neutral rather than slightly acid, and was 
swarming with organisms of different kinds. There 
was a great increase in the number of the Vibriones, 
and also of the Micrococci both free and loculated. 
One of the large groups of the former is shown in 
Fig. 31, A, partly stained with eosin. There were 
also groups having all the appearance of Sarcine, 
one of which is shown in B. Lehmann and 
Neumarin. say (/oc. cot. p, 151): “It is our cone 
viction that the Sarcina is connected with the 
Micrococci by unbroken transition forms,” and the 
appearance of the groups of Sarcine here found 
certainly lent support to this view. Torulz were 
also found, such as are represented in Fig. 32, B, 
together with one small mass of Mould about the 
size of a small pin’s head, from which myriads of 
hyphze were issuing in all directions, some of 
which, at the periphery of the mass, are shown in 
Fig. 32, A. The advantage of leaving tubes con- 
taining such a solution a very long time before they 
1 In reference to what follows, it is well that certain facts concerning 
the paucity of micro-organisms in the air should be borne in mind, as 
recorded by an eminent bacteriologist, Dr Allan Macfadyen, in a 
Friday evening discourse at the Royal Institution in June 1900 (see 
Proceedings, vol. xvi. p. 451). Speaking of a special investigation 
made by himself and Mr Lunt, he says: “In the open air of London 
there was on an average just one organism to every 33,300,000 dust 
particles present in the air; and in the air of a room, amongst 
184,000,000 dust particles, only one organism could be detected.” 
