SOME FEATURES OF INTEREST IN THE ORDER OF CONIFERS, ^ 



Genealogy. 



But whilst it is utterly impossible to say when Conifers 

 made their appearance on the surface of the globe, we have, 

 nevertheless, some means of ascertaining with a high degree of 

 probability what their lineage has been. All the available 

 evidence goes to show that we must look for the ancestry of the 

 Conifers among some group now extinct, but which must have 

 been closely allied to existing Lycopods and Selaginellas. 

 This presumption is based upon certain very remarkable 

 peculiarities in the organs of fertilisation — in the pollen as well 

 as in the ovule — originally observed in part by Robert Brown, 

 and subsequently investigated in detail by Hofmeister, Stras- 

 burger, and many others. I cannot enter upon these points at 

 any length, but I may put it thus : If, as is now proved, the 

 construction of the innermost penetralia of the microspore and 

 of the megaspore (of the pollen and of the seed, if I may so 

 speak) be the same, if their method of working be substan- 

 tially identical in the groups before mentioned, or if, to be 

 more precise, the ovule of a Conifer contains a megaspore with 

 a prothallus bearing archegonia, then the relationship between 

 the Conifers and the higher Cryptogams must surely be con- 

 sidered to be established. 



Stages of Geowth. 

 There are other pieces of evidence which can be appreciated 

 by any of us, even by those who are not trained microscopists, 

 and they can be worked out better in the garden or in the 

 forest than in the herbarium. They depend on the circum- 

 stance, which seems to be generally admitted, that the progres- 

 sive changes which may be observed during the development 

 and growth of each individual living creature are the reflections 

 of similar changes and of similar stages of growth in their 

 ancestry. Now the growth of Conifers presents a very close 

 resemblance to that of Lycopods and Selaginellas. Of them- 

 selves these resemblances might be treated as merely superficial 

 and unimportant, but when considered in association with those 

 other embryonic " characters " that I have mentioned, it is 

 impossible to resist the conclusion that we have to deal with 

 '-'homologies" — that is, with real affinities, not with superficial 

 or misleading resemblances. 



B 2 



