356 MR. 8. LE M. MOORE'8 STUDIES 
longer-leaved type *, for it surely is at least rash to argue that 
by natural selection or otherwise the amount of chlorophyll in the 
isodiametral cells has been increased, in face of the fact that, the 
long cells certainly contain no superabundance of that sub- 
stance. 
Since S. Martensii flourishes in the shade, it might safely be 
predicted that direct sunlight is not necessary in order to cause 
change in the position of its chlorophyll bodies. The accom- 
panying diagram shows all the information I have been able to 
= + 
Diagram showing the positive critical point of Selaginella Martensii; below 
it the epistrophic interval of Funaria hygrometrica on the same day (in 
August) and during the same hours. 
collect. regarding the plant’s epistrophic interval. The position 
of the positive critical point was fixed by laying out leaves under 
precisely similar circumstances to those detailed in the former 
memoir; with each set were placed some healthy leaves of Funaria 
hygrometrica, Linn. T. The duration of the experiment was two 
hours, ainple time for apostrophe to have declared itself in the 
lowest of the proximal isodiametral cells close to the oblique 
portion of the large leaves. There is nothing to add at present; I 
cannot even say whether or no the epistrophic interval runs up to 
the negative end of the photrum—a plant with negatively (partially 
orentirely) fragmented and occasionally apostrophized chlorophyll, 
which was placed in the lowest light, with a view to ascertain 
* I do not know whether there are species of Selaginella with leaves having 
& long-celled upper epidermis and fragmented chlorophyll, and others with 
very short leaves provided, like the small leaves of S. Martensii, with isodia- 
metral upper epidermal cells throughout, This matter is perhaps worth inquir- 
ing into. 
t In the former memoir (Journ. Linn, Soc. Bot. xxiv. 1887, pp. 200-251), 
it was stated that the epistrophic interval of F. hygrometrica, there drawn (in 
autumn) as reaching the positive end of the photrum, would probably be found 
during the summer months not to reach so far to the right. This surmise has 
proved correct ; at least for the month of August. 
