372 



SCIENCE 



[N. S., Vol. XL., No. 1028 



It is noteworthy how large a number of 

 botanists dissent from any absolute nega- 

 tion of the influence of the environment 

 upon the genesis of heritable characters. 

 Partly this may be due to a sense of the 

 want of cogency of the argument that the 

 insufficiency of the positive evidence 

 hitherto adduced justifies the full negative 

 statement. But I think it finds its real 

 origin in the fact that in plants the genera- 

 tive cells are not segregated early from the 

 somatic. In this respect they differ widely 

 from that early segregation of germ-cells 

 in the animal body, to which "Weismann 

 attached so much importance. The fact is 

 that the constitution of the higher plants 

 and of the higher animals is in this, as in 

 many other points, radically different, and 

 arguments from the one to the other are 

 dangerous in the extreme. Those who in- 

 terest themselves in evolutionary questions 

 do not, I think, sufficiently realize that the 

 utmost that can be claimed is analogy be- 

 tween the higher terms of the two king- 

 doms. Their phyletic separation cer- 

 tainly dates from a period prior to that of 

 which we have any knowledge from the 

 fossil record. Let us give full weight to 

 this fact, as important as it is indisputable. 

 The early definition of germ-cells in the 

 animal body will then count for nothing in 

 the evolutionary problem of plants. More- 

 over, we shall realize that the plant, with 

 its late segregation of germ-cells, will pre- 

 sent the better field for the inquiry 

 whether, and how far, the environment 

 may influence or induce divergences from 

 type. From this point of view the wide- 

 spread opinion among botanists that the 

 environment in some sense determines the 

 origin and nature of divergences from type 

 in plants should command a special in- 

 terest and attention. 



I must now draw to a close. I have 

 passed in review some of your more notable 



plants, and pointed out how the Austral- 

 sian flora, whether living or fossil, includes 

 in unusual richness those evidences upon 

 which the fabric of evolutionary history is 

 being based. I have indicated how this 

 history in certain groups is showing ever 

 more and more evidence of parallel de- 

 velopment, and that such development, or 

 convergence, presses upon us the inquiry 

 into the methods of evolutionary progress. 

 The illustrations I have brought forward 

 in this address clearly show how important 

 is the positive knowledge derived from the 

 fossils in checking or confirming our deci- 

 sions. Paleophytology is to be prized not 

 as a separate science, as, with an enthusi- 

 astic view restricted between blinkers, a 

 recent writer has endeavored to enforce. 

 To treat it so would be to degrade it into a 

 mere side alley of study, instead of hold- 

 ing it to be the most positive line that we 

 possess in the broad avenue of botanical 

 phylesis. An appreciation of such direct 

 historical evidence is no new idea. Some- 

 thing of the same sort was felt by Shakes- 

 peare three centuries ago, and it remains 

 the same to-day. Nay more : — it may lead 

 us even to forecast future possibilities. In 

 following our evolutionary quest in this 

 spirit we shall find that we are indeed — 



Figuring the nature of the times deceased, 

 The which observed, a man may prophesy 

 With a near aim^ of the main chance of things 

 As yet not come to life. 

 (King Henry IV., Part II., Act iii. Scene i.) 



F. 0. Bower 



TSE BECMEASING BIBTE RATE OF THE 

 GERMAN EMPIRE 

 During the 30 years following the war with 

 France the population of Germany increased 

 enormously while the population of France 

 remained almost stationary. But at the be- 

 ginning of the new century the birth rate in 

 Germany began to decline and is still declin- 

 ing at a rapid rate. In an article in No. 18 of 



