202 Northern Ne^vs. 



but the anomalous structure of the leaf must be remembered' 

 (Figs. 6 and 8). 



Reverting to the seedling, the sheathing base of the small 

 foliage leaf swells to form the first bulb, and has the plumule 

 safely ensconced within it. Examination will shew that the 

 apices of the bulbs of both seedhng and mature plants appear 

 as if they had been cut with some sharp instrument. The 

 explanation is that a transverse layer of corky tissue is formed 

 there before the rest of the leaf has decayed to that point, and 

 its position can be made out by a thin transparent band some 

 time previous to actual decay. This layer of cork, in addition 

 to healing the wound, so to speak, prevents the access of fungi 

 and moisture whilst the bulb is at rest in the damp soil it usually 

 inhabits. Towards the end of May the tiny bulb now formed, 

 comes to rest. 



The next growing season (winter months chiefly), in addition 

 to several fine absorptive roots, a thick root is given off from 

 its base, which, when firmly fixed by root hairs near its tip, 

 contracts and pulls the bulb deeper in the soil 

 (fig. 5 cr). Each subsequent year the foliage 

 leaf produced becomes larger until maturity 

 is reached.* When there are two leaves, the 

 base of the innermost one, which forms the 

 bulb, becomes larger ; consequently longer, and 

 stronger, and more numerous contractile roots 

 are required. In adult plants the new bulbs 

 are formed a little higher in the soil than those 

 1^4 they replace ; so these peculiar roots are 

 necessary to pull them down to the proper 

 level which appears to be about four inches 

 below the surface to tip of bulb. 



Fig. 5. — Two year old bulb (b) resuming growth after period of rest 

 CR, contractile root ; fr, fine roots ; s, scar of last year's leaves ; Sc 

 sheathing scale leaf. 



NoTE.^First formed bulb at this season differs only in being smaller. 



[To be continued). 



' Was Darwin Right ? ' is the title of a discussion being carried on 

 in a contemporary. 



' The Claws of Insects ' was the subject of the Presidential Address to 

 the Entomological Society. It was delivered by Mr. C. O. Waterhouse on 

 January 20th, 1909, and is printed in the Society's Transactions for the 

 year 1908, part V. 



* Four to five years, perhaps, under favourable conditions. 



Naturalist, 



