1890.] NEW-YORK MICROSCOPICAL SOCIETY. 75 



brane, which very soon dehisces, and out of this spherical cell 

 comes its occupant, somewhat bean-shaped or pseudo-crescent, 

 if you like, with two cilia by which he sails away, a bashaw of 

 two tails, leaving his jacket behind him. 



De Bary, says : " The distinguishing mark of the Sa/>ro/egnia 

 is that the spores are in the motile state as they issue from the 

 sporangium, and that the branch of the thallus which bears the 

 sporangium grows through it when it has discharged its spores." 

 The walls of the emptied sporangium have become much 

 thinned through absorption by the sporidia, so that the cylindri- 

 cal section below, which is to become a sporangium, grows 

 through this emptied capsule, becoming in its place the apical 

 cell. The sporules thus emitted are at once motile spores, 

 zoospores, or quasi-vitalized seeds, ready to germinate after a 

 little change. It is like taking a shortened course, in which the 

 symbiosis in Nature is dispensed with for the nonce and, 

 strictly speaking, this is nowhere so anomalous as in these very 

 fungi, where the laws oi fructification are peculiarly complex. 

 The common grape vine fungus now so destructive, passes in its 

 development through eight stages or forms of spore, ere the 

 ultimate spore form is reached. 



We have seen that the motile spore or zoospore of the spor- 

 angium plays much the simpler role. Yet even this spore is 

 subject to curious changes. In the Saprolegnia it emerges in 

 an ovoid form, with a pair of cilia. It is then little more than 

 an amoeboid. It is not a cell proper. But this may need a 

 word. 



No one has seen the film which holds the contents of the 

 dewdrop. This is left to conception. An amoeba is the sim- 

 plest form of animal life — a speck of sarcode, tissueless, a 

 structureless living animal substance. Now when we see it 

 pushing out pseudopodia and retracting them, we must conceive 

 a peripheral or containing layer or film of the protoplasm or 

 sarcode ; so is it with our motile ovoid sporule when it leaves the 

 mother-cell, the sporangium. Its cilia are simply projected 

 tubes of the peripheral film. With these it can turn upon itself 

 and propel itself also. Its travelling soon ends, when it comes 

 to rest, and its cilia are withdrawn, in fact absorbed. Very soon 

 this ovoid amoeboid spore becomes spherical, and is invested 



