96 



j>r chaiitie of 

 temperature. 



How then ' 



ON TIIL STUDY OF MOSSES. 



regular order mentioned in the experiment. Neither diet 

 the motion take place IVoiti chnnge of temperature, for the 

 temperature was not altered. 



A great many questions 'A'ill here suggest themselves, as, 

 How does it happen, that the motion is produced? Flow 

 does it become so extensive? How comes it that there are 

 such regular motions and p'_&eo? &c. I expect at some 

 future period to be able to throw some light on this difficult 

 subject, but in the mean time must beg leave again toquote 

 Dr. Smith's words, and say, that " it is vain to attempt any 

 mechanical solution of the phenomenon" above related, 

 which would seem to depend on an " exquisite irritability" 

 in the plant itself. 



Sundew not 

 affected by 

 light, heat, 

 iiioistine, or 

 their o.ppo- 



P. S. I might have added at the end of my lust, tliat the 

 leaves of the drosera.rotundifolia and longifolia remainconJ- 

 pletely expanded duri tig- the liottest sunshine and driest wea- 

 ther; during the coldest and wettest weathei*; during the 

 greatest d a rlinessjand finally duringthe brightest lightof d;iy. 

 Here then, neither heat, cold, dryness, dampness, darkness, 

 nor light in general at all effect the leaves; but if a foreign 

 body is applied to tlie leaf so as to stimulate, then it will 

 shut up in the mantier related in my lust. How vfill this 

 agree with Mrs. Ibbetson's ideas ? 



IV. 



Queations on tlie Study of the Mosses. In a Letter from a 

 Correspondent. 



SIR, 



To Mr. NICHOLSON. 



How should 11 Siioidd consider myself obliged, if you should think the 



ii.L ni.s ^^ ,e foiiowintr questions of sufficient import to merit a place in 



your Journ.. I. hi commencing the study of the musci, should 



* Til is is to be taken in a limited sense, i. e. only during the expan- 

 Moii of the k-avcs, :i'Jt during the culJ of winter, 



the 



