70 TRANSACTIONS, NATCRAL HISTORY SOCIETY OF GLASGOW. 



The existence of a truly wind-fertilised Cryptogam 

 has not yet been demonstrated — that is to say, we 

 do not know of any instance in which the wind 

 conveys a motionless antherozoid to the archegonium, 

 as is done by water currents in the case of the 

 Florideae. Dogmatically to assert that no plant 

 exists in which the antherozoids are carried by the 

 wind would of course be hazardous in the present 

 state of our knowledge. Very possibly some of 

 those reproductive structures of unknown function, 

 such as the spermogones of the Uredineee, may yet 

 be found to be adaptations in this direction. If a 

 wind-fertilised Cryptogam should ever be discovered, 

 we might expect the archegonium to show a special 

 provision for the reception of the antherozoids. 

 Meantime the only structure we know among 

 flowerless plants w^hich in function aj^proaches the 

 feathery stigma of a grass is the trichogyne of the 

 Floridese, to which we have before referred. 

 Although we are not acquainted with any flowerless 

 plant which, strictly speaking, is "vvind-fertilised, 

 still from another point of view we may regard the 

 higher terrestrial Cryjptogams as being wind- 

 fertilised. In Ferns, where only one kind of spore 

 is produced, there is but one sowing, or at least 

 only one in which the wind is concerned. The 

 spore, on germination, gives rise to a flat leaf-like 

 l^rothallus, which bears on its under surface male 

 and female cells— antheridia and archegonia. Each 

 antheridium becomes a new centre of dispersion 

 discharging motile ciliated antherozoids. These 

 swarm over the entire surface of the prothallus, so 

 that some of them almost inevitably enter the 

 opening of the archegonium and fertilise the 

 oosphere. Where the same prothallus bears both 

 antheridia and archegonia, and where there is no 

 necessity for cross - fertilisation, the swarming of 

 the antherozoids may be sufficient to effect their 

 proper delivery, and in that case we can hardly 

 regard the wind as playing any part in the process 



