tlirew out upwards of 1212 pairs ! This was hardly to be anticipated, hut may certainly give us confidence in 
the substantial validity of the numerical result reached. This result is clearly independent of any extraneous source 
hindering the production of any sori at all on the frond. About a third of the ferns in the series (31 in 101) had one 
328 
PKOFESSOR K. PE ARSON AND OTHERS ON 
