PHYSIOLOGY OF REPRODUCTION IN PLANTS. 245 



the case. Some Liliaceous plants never produce seeds, 

 unless experimentally forced to do so, because the stores of 

 food-materials are all deflected into the bulbs — the rudi- 

 mentary gametophyte is starved and dies of inanition, and 

 yet we have no reason to believe that the ever-continued 

 sporophyte suffers. Species of Musa and many other 

 plants have probably never formed seeds for thousands 

 of years, and in such cases as these and the potato and 

 many other flowering plants, where the sporophyte is 

 propagated vegetatively, we have no reason to believe that 

 the plant suffers, though in many of them no trace of the 

 gametophyte generation ever appears at all. 



It looks then as if the environment may have more to do 

 directly with the origin of reproductive organs — and with 

 that of other structures also, be it said — than is often assumed. 



In these classes of cases it is soon evident that matters are 

 too complex for direct experimental treatment, at least just 

 now, and we may feel very sure that all hope of solving 

 fundamental questions concerning the relations between the 

 morphology and physiology of sexual organs must be 

 approached through the lower and simpler forms of life. 

 Striking illustrations of variation, or of morphological in- 

 consistancy, are doubtless more easily obtained from higher 

 plants than from lower, and probably because the very 

 complexity of their organisation renders them more easily 

 varied — deflected out of the normal course — on a similar 

 principle to that which renders a tall house of cards more 

 easily overthrown by a shock than a less ambitious erec- 

 tion would be ; but when it comes to studying the factors 

 at work which induce the variations it is perhaps logical to 

 expect that the study of the lower plants will be more pro- 

 ductive of results. But we must not forget that a very 

 slight variation in a lower plant may imply more than a 

 much more obvious change in a higher one. 



In this connection the recent publication of Kleb's 

 experiments on the conditions affecting the development of 

 reproductive organs in some Algae and Fungi is one of the 

 most valuable and stirring contributions to botany of this 

 decade. 



