34 Messrs Purvis and Warwick, The Influence of 
No light. Cerevisise was similar to that in the white light ; 
and Pastorianus as in white and red, although it was 
doubtful if there was much advance. 
6 p.m. Bed light. In Cerevisise some cells were approaching the com- 
pletion of sporulation ; Pastorianus shewed a very slight 
advance ; the indications of spores were not very strong. 
Green light. In Cerevisise there were fair indications ; in 
Pastorianus less advanced than in red. 
Blue light. Very Aveak indications in Cerevisise; whilst 
Pastorianus were unchanged. 
White light. Very strong indications in Cerevisise, although 
not so advanced as in the red ; in Pastorianus the ap- 
pearance was like that in the red. 
No light. In both Cerevisise and Pastorianus the indications 
Avere similar to those in the green. 
11.45 p.m. Red light. In Cerevisise there was a marked advance on 
the last ; also Pastorianus had advanced very slightly. 
Green light. Cerevisise had slightly advanced, Avhilst Pasto- 
rianus had not changed apparently. 
Blue light. Very faint indications in Cerevisise; but ap- 
parently no indications in Pastoiianus, except one or 
two cells here and there. 
White light. Cerevisise sheAved marked advance in sporu- 
lation though not so much as in the red ; Pastorianus 
remained unchanged. 
No light. Cerevisise shewed marked advance, though not so 
well developed as in the Avhite light, but much more 
than in the green. Pastorianus Avas A r ery similar to that 
in the green and the Avhite light. 
It appeared as if the Pastorianus cells Avere not very healthy, 
and no further observations Avere made upon them in this series. 
The observations were confined to the Cerevisise cells during the 
rest of the experiment. 
20 February. 
10 a.m. Red light. CereAusise cells had more perfect spores than 
when examined at 11.45 p.m. (19 February). 
Green light. One or two cells of CereAfisise had sporulated 
as in red, white light and no light ; but the majority 
had not advanced, and the cells were becoming empty 
and thin looking. 
Blue light. The indications in Cerevisise appeared to be 
vanishing ; the cells Avere very empty. 
White light. Some spores perfect in Cerevisise. 
No light. Cerevisise shewed marked advance ; and the 
sporulation had iioav proceeded as far as in the Avhite 
lieiit. 
