270 ANOMALIES OF DEVELOPEMENT. CHAP. V. 



merable fibres from the surface, which become 

 again subdivided into fibres still more minute, and 

 give to the whole an appearance something re- 

 sembling that of the tail of a fox ; which has accord- 

 ingly been denominated by Du Hamel the fox-tail 

 root. (PI. IX. Fig. 5.) This anomaly I have fre- 

 quently observed in the root of Willows growing 

 by ponds, of which the main offset has been about 

 eighteen inches in length, and the terminal and 

 lateral subdivisions six or eight inches. Du Hamel 

 relates an example of the same anomaly, which he 

 had observed in the case of a root that had insi- 

 nuated itself into a water-pipe, where it increased by 

 the sending out of a prodigious number of small 

 fibres, till at last it occupied the whole diameter 

 of the pipe and stopped the current of the water.* 

 Perhaps the above anomaly is merely the result of 

 an extraordinary effort of the vital principle to adapt 

 itself to the circumstances in which it is placed, by 

 extending the surface and multiplying the subdivi- 

 sions of the root, for the purpose of the more easy 

 abstraction of the oxygene of the water. 

 Roots that But sometimes an anomaly takes place which is 

 fftrousTJ directly the reverse of the above. The Phleum 

 bulbous pratense when growing in a moist soil, which it natu- 

 rally affects, is uniformly furnished with a fibrous 

 root ; but when growing in a dry soil, where it is 

 also often to be found, it is furnished with a bulbous 

 root. The same is the case also with the Alope- 



* Phys. ties Arb. liv. i. chap, v. 



6 



