56 Some Wayside Problems 



Another common plant, the Lady's Smock (Cardamine 

 pratensis), frequently exhibits the same sort of change. 



A less frequent instance of a striking change of 

 habit suddenly occurring is afforded by the little 

 scentless Dog- Violet (Viola sylvatica), which is so 

 common everywhere in April and May. To look 

 at the lowly prostrate plant, whose family has been 

 taken as the emblem of humility, nothing could 

 seem further removed from the rampant climbers 

 with which I began, plants that employ every 

 parasitical device to thrust themselves into promi- 

 nence. Yet I have known the Violet do just the 

 sarne. It was on the borders of the little Welsh 

 river Aled, late in October, many years ago, that an 

 unusual-looking blue flower half way up a hedge 

 caught my attention. Examination showed this to 

 belong to a long straggling stem, two and a half feet 

 long, but an indubitable Violet. Instead of staying 

 its growing operations at the usual season, this 

 specimen had, to gain its private ends, continued 

 to develop its main shoot, from which sprang off 

 laterally alternate leaves, with flowers in their axils, 

 and it had multiplied these leaves to the number 

 of sixteen. Of flowers there had presumably been 

 an equal number. That which caught my eye was 

 the only one still blooming, but below it were several 

 seed-pods. Altogether, except for the circumstance 

 that it was a Violet, nothing could less have 

 resembled that plant 



It would be easy to extend the list of such phenomena, 

 but the catalogue might not improbably grow wearisome, 

 and those which I have mentioned are sufficient for my 

 object. It is quite clear that there is abundant matter 

 for observation within reach of all, and it seems to me 

 no less so, that we shall find reiterated to us in many 

 ways the lesson of our own ignorance. The making of 

 theories is a fascinating pursuit, and nothing is more 

 attractive than to find facts tally with a theory we have 

 made. There is therefore no little danger lest con- 



