Arable Land 



wait till the crop is removed, or the potato-stalks are 

 rotting on the ground. 



Mr. Ridley records an unusual exactness in flowering 

 for certain orchids and Dipterocarps near Singapore. 

 A Dendrobium flowers with the greatest punctuality 

 every six weeks. On the proper day every plant in the 

 district is white with blossom, but next day one can find 

 nothing but withered flowers. This habit seems also to 

 be common with Bromheadias. 3 



It is really just as wonderful to find in one field, 

 thistles, Scleranthus, and many other weeds, all shedding 

 their seeds within exactly a day or two of one another. 



It is more difficult to explain why it is only in some 

 years that almost every bamboo plant is found in flower, 

 or why certain Shoreas and Hopeas should regularly 

 blossom within one or two days of one another, at 

 intervals of six years. 



Weeds have several very remarkable peculiarities, 

 besides their ingenuity in the way of flowering exactly 

 when it suits them best. Most of them possess under- 

 ground runners or rhizomes or fleshy roots, which are 

 placed just too deep for the plough or spade to interfere 

 with them. 



Bishop's weed, coltsfoot, thistle, bracken, and several 

 others cannot be eradicated by the plough, for their 

 starch-filled stems or roots are just out of reach. Even 

 if one could manage to drive a cultivator through these 

 roots so as to cut them in pieces, this would not be of 

 much use. It has been shown that a piece of these 

 runners (thistle), one quarter of an inch in length, is 

 capable of producing a complete new plant. 



It is very disheartening to try and remove the thistles 

 from a field by mowing them down. But it can be 

 done ; for, if the thistles are cut over three or four 

 times a year, and this continued regularly for four years, 



257 R 



