138 PLANT LIFE. 



Dictyoteae to the Fucaceas, the highest type of " oogamous " 

 reproduction, consisting in the impregnation of a compara- 

 tively large oosphere by a number of minute antherozoids ; 

 the Syngeneticffi being regarded as a retrogressive offshoot 

 from the Phseosporeae ; and (3) the Confervoidese hetero- 

 gamae ; including the Sphsropleacese, CEdogoniacese, and 

 Coleochsetaceae, from which latter family the Pediastrese 

 are probably derived by retrogression. The Coleochsetacese 

 lead up directly to the highest type of structure attained by 

 the Thallophytes— the Florides, from the highest form of 

 which we have probably several retrogressive branches, viz. 

 the Nemaliete, the Lemaneacese, and the Bangiaces. The 

 author suggests that the Ulvacese may possibly be derived 

 from the Bangiaceae by further retrogression. ^ 



Class IL— FUNGI. 



The present class includes above thirty thousand so- 

 called species, varying in size from microscopic individuals 

 up to the comparatively gigantic " puff-balls," which in some 

 instances exceed a foot in diameter. The variety in con- 

 sistency is equally marked, a sequence being present be- 

 tween the short-lived, ephemeral " moulds " that disappear 

 on the slightest touch, to the large, perennial species of 

 Polyporus, where the tissue is often as hard and compact 

 as that of the hardest wood. 



In such an enormous assemblage there is, as would be 

 expected, a very varied range of differentiation and division 

 of labour, both in the vegetative and reproductive portions ; 

 but more especially the latter, as in common with other 

 groups that have degenerated to a state of parasitism, the 



'^ Jotirnal of the Royal Microscopical Society, 1887, p. 786. 



