NOTICES OF BOOKS AND MEMOIRS. 3877 
‘ e the apex; but in this case the radicle turns 
towards the touching object, and curves round it as a tendril does 
round a stick. 
’ Then follow experiments of an exhaustive nature, carefully 
e whole a) , 
carefully attached to the side of the extreme apex, cause the radicle 
This work is well done, and we venture to think that it opens 
i indeed, the authors would 
), geotropic, nd innate 
wn, sensitiveness to the touch of a 
e tip to one side, and a sensitiveness to 
moisture attracting it in an opposite direction, there 1s a comp. 
and beautiful problem before one who attempts to picture the 
insinuation of a radicle into the soil. 
We ar ‘need of the accuracy of the conclusions 
as to causes which render pecan! — ge —. 
=. i mary ones, when the latter are destroyed or 
capable of replacing pri would be very difficult to strike the 
balance between even the external forces which direct a ranch or 
rootlet into that portion of the available space which is least 
3D 
