CRYPTOGAMS 



379 



together with sporangia, in other cases alone, are also adapted for 

 dispersal in air. They arise by a process of budding and abstriction 

 from the ends of certain hyphae which are usually raised above the 

 substratum as special conidiophores. 



The sexual organs of the Phy corny cetes are in many ways 

 peculiar, and the two groups of the Oomycetes and the Zygomycetes 

 are distinguished according to their nature. In the Oomycetes, 

 which stand nearer to the Green Algae, oogonia and antheridia are 

 found ; the contents of the latter enter the oogonium by means of a 

 tubular outgrowth, and after fertilisation oospores are formed. In 

 Monoblepharis alone are free spermatozoids found. The sexual 

 organs of the Zygomycetes are alike, and on conjugation a zygospore 

 is produced. They are usually multinucleate and thus are morpho- 

 logically comparable to a whole gametangium of an isogamous Alga. 



Multinucleate gametangia, oogonia, and antheridia, which fuse 

 directly with one another, without the separation and escape of the 

 individual gametes, are generally termed CCENOGAMETES. 



Order 1. Oomycetes 



1. Only in the small family of the Monoblepharideae ( 51 ) are free ciliated 

 s]n-nii:itozoids liberated from the antheridia. In the other Oomycetes the multi- 

 nucleate contents of the antheridium do not divide into separate spermatozoids, 



Pio. 315. Monoblepharis sphaerica. End of filament with terminal oogonium (o) and an antheridium 

 (a) : 1, before the formation of the egg-cells and spermatozoids ; 2, spermatozoids (s) escaping 

 and approaching the opening of the oogonium ; 3, osp, ripe oospore, and an empty antlieridinm. 

 ( After CORNU, x 800.) 



but are directly introduced into the egg-cell by means of an outgrowth of the 

 antheridium. 



The species of Monoblepharis live in water upon decaying remains of plants. 

 Asexual reproduction is effected by means of swarm - spores, formed in large 

 numbers in sporangia. The oogonium, which is usually terminal, contains only a 



