CHAP. V.J RELATIONSHIP AMONGST PLANTS. 175 



feature is the absence of high dififerentiation in the 

 fertilized body or oospore previous to immediate germi- 

 nation. The cutting down of one of the, two phases or 

 generations — the sexual one — is carried to a very con- 

 siderable extent in CryptogamSj that is in plants that 

 yet have motile antherozoidsj and consequently reach 

 the female part to be fertilized through the agency of 

 water ; but as plant-life extended from its original 

 aquatic habitat, water as the agent for bringing the 

 male or fertilizing body in contact with the female was 

 gradually superseded as already explained, by other 

 agents; consequently the male body lost its motility 

 and became transported, by wind or insects. When 

 evolution reached the point where the sexual phase as a 

 distinct structure had been arrested, and the old motile 

 antherozoid replaced by non-motile pollen, also a higher 

 development of the fertilized oosphere resulting in the 

 formation of an embryo previous to immediate germina- 

 tion, then these combined characteristics constitute the 

 key-note to the botanist's conception of a Phanerogam, 

 as opposed to a Cryptogam, which it will be observed 

 turns in reality mostly on the particular way in which 

 the male or fertilizing body is conveyed to the female. 

 But Phanerogams did not appear with a spurt as a new 

 creation ; in other words, the features given above as 

 characterizing a Phanerogam did not appear simul- 

 taneously, and even in Phanerogams the rudimentary 

 remains of structures characteristic of Cryptogams, as 

 the prothallus or sexual generation, are still present in 

 Gymnosperms. On the other hand such features as 

 the highly developed embryo, characteristic of Phane- 

 rogams, is clearly indicated in some of the higher 



