VAUCHEKIACEJ]:. 119 



In great number (20, 30, or more) they enter the neighbouring orifice 

 of the sporangium, which they fill almost entirely, penetrating through 

 the portion of the cutaneous layer remaining, which, though without 

 any definite boundary, offers a solid resistance to their further penetration 

 into the sporangium. The corpuscles continue thus to struggle forwards 

 into the cutaneous layer for more than half an hour, bounding against 

 its outer surface they retreat, again push forwards, again retreat, and 

 so on, in an uninterrupted succession of assaults and retreats. 



After this commotion has lasted some time, an abrupt boundary line 

 suddenly appears in the outer aspect of the cutaneous layer, the first 

 indication of a tunic forming around the contents of the sporangium 

 which were before bare. From this moment the mobile corpuscles are 

 separated from the cutaneous layer by a membrane which effectually 

 prevents their further action upon the contents. They continue, it is 

 true, to move to and fro, and this movement often lasts for hours 

 together, but at last they perish in the rostrum itself. Even after the 

 lapse of several hours the dead corpuscles may be seen in the rostrum, 

 lying on the front of the sporangium, until at last they are completely 

 dissolved, and all vestige disappears. 



The cutaneous layer surrounding the green contents of the sporangium 

 becomes transformed, after impregnation, into the coat of the true spore, 

 which, thus formed, represents a large cell occupying the whole of the 

 sporangium, surrounded on all sides by the persistent tunic, which is 

 open in front and prolonged into the rostrum. 



In this condition the spore remains for some time longer without being 

 thrown off from the parent tube on which it was produced, but the 

 colour of its contents gradually becomes paler and paler. The spore is 

 at last rendered quite colourless, and presents in its interior only one or 

 more largish dark brown bodies. When it has lost all colour it is 

 detached from the parent tube, in consequence of the decay of the 

 membrane of the sporangium enclosing it. After some time, say three 

 months, the spore suddenly resumes its green colour, and immediately 

 thereupon grows into a young Vaucheria exactly resembling the parent 

 plant. 



An abstract of the memoir from which the above details were obtained 

 was published in the " Quarterly Journal of Microscopical Science " for 

 1856, (Vol. iv., p. 63). 



During the present winter Mr. Frederic Bates, of Leicester, has called 

 our attention to some plants of V. scssilis, taken from beneath the ice 

 in a pool, The first feature which presented itself was the septation of 

 the threads, many of them being divided into numerous articulations 

 three or four times the length of the diameter in the upper portion of the 

 thread, but longer below. This unusual septation, as it appears to be, 

 was general throughout the gathering, but the threads bearing oogonia 

 were more rarely divided, but sufficiently so to remove any doubt as to 

 the threads being genuine threads of Vaucheria, which at first we must 

 confess to have doubted. The question which next arose was as to the 

 purpose for which this septation had taken place, and an answer sug- 

 gested itself in the collection of the cytioplasm into denser masses 

 towards the centre of the cell, with most evident differentiation into oval 

 bodies, resembling zoogonidia in course of formation. The time of 

 observation has been short, but long enough to raise a suspicion in our 

 minds that another form of fructification, by means of zoogonidia, takes 

 place in VavcJieria, and the occurrence of germinating spores in various 

 early stages in the water in which the Vaycheria was being preserved, 

 lends strength to this suspicion. It is quite true that Vaucheria haa 

 been often and patiently studied, and no intracellular swarm-spores 

 detected ; yet it maybe possible that, under certain conditions, they may 

 be produced. We are patiently waiting in hopes of obtaining active 

 zoogonidia. 



8 



