NOTE ON RASPBERRY ROOTS. 207 



There can be no doubt as to the fact of these curious curvatures 

 when plants are grown in leaf-mould, or of the advantage which 

 the give-and-take of the root spirals will afford to the stem when 

 shaken or pulled by animals passing through. It is, however, 

 almost impossible to prove that the free part of the roots coils in 

 this way through circumnutation only. The most recent paper 

 by Professor Macdougal,^ of which we have only seen an abstract, 

 seems to show that, if a stimulus be applied to a very young root 

 cell, its effects may remain dormant for a considerable period. 

 These coiled roots ma^j when very young, have been in contact 

 with stones, and the result would only appear w^hen they are 

 mature. Stones are, however, not common in leaf-mould. 



One might also say, that if the young root were ever so slightly 

 coiled, the subsequent contraction described above would ac- 

 centuate these curves, and produce spirals. But this slight 

 coiling would be simply circumnutation in an early condition. 



On the whole, the simplest explanation seems to be that 

 the root, when firmly fixed, behaves in this case exactly in the 

 same way as the tendrils, and the result is a very perfect 

 mechanical adaptation to its surroundings. 



^ Macdougal, Botanical Gazette, Vol. XXIII., 1897, No. 5. 



