Sketch of the Class Fungi. 295 



that which takes place in Conjugated of the class Algae, and especially 

 in the genus Closterium. The tips of two branches approach, join, 

 and form by their junction a verrucose sporangium, in which the spores 

 appear to result from the mixture of the contents of the two. But 

 this mixture, as we may easily imagine, cannot take place without 

 the resorption of the septum at the point of juncture, which in fact 

 takes place. Nevertheless, it would appear that the copulation is 

 not indispensable to the accomplishment of the function, since, when 

 the two branches do not touch, a single sporangium is formed at the 

 extremity of one of the two, or else, though more rarely, one appears 

 on each extremity*. 



In their germination, which is not now matter of controversy, 

 there is a simple elongation of a single pole, or of two opposite poles, 

 of the epispore of the sporidia {mono-dinema) ; or else, according to 

 Corda (/. c.ii. p. 26, t. xiii. fig. 97, No. 21), this bursts like the testa 

 in the true seeds of Phaenogamous plants, to make way for a filament 

 susceptible of reproducing the plant from whence it emanates, or at 

 least of concurring in its reproduction. It appears, indeed, to be 

 averred, that in many fungi, especially amongst those which are 

 highest in the series, one, or even several sporidia are not sufficient 

 for the production of a new individual. Nature, in infinitely multi- 

 plying the number of seeds in these plants, seems to have wished to 

 initiate us into the secret of their propagation. The mycelium, which 

 arises from the germination of the sporidia, should seem to be unable 

 to work the almost instantaneous growth of an Agaric ; for example, 

 if it were composed of too small a number of filaments, themselves 

 limited in their vegetative powers. It is then, in this case, only by 

 the simultaneous concourse of an immense number of sporules that 

 we can hope to obtain the desired result. But even this is not always 

 sufficient ; many other conditions are necessary ; such as the choice 

 of situation or matrix, atmospherie or meteorological momenta, and, 

 above all, the season. If I can form any sure conclusion from some 

 experiments which I have made during the microscopic investigation 

 of Botrytis Bassiana (Muscardine), nature is not so peremptory in 

 the lower fungi ; for after having succeeded in separating upon the 

 stage of the microscope a single sporidium, I have not only caused 

 it to germinate and run through all the phases of its new existence, 

 even to ithe production of the fruit ; but what is more surprising, I 

 have obtained, unexpectedly, the same result on a simple plate of 

 glass placed under suitable conditions of light, heat, and moisture. 

 The same experiment was equally successful in Ascophora Mucedo. 



We have at last arrived at the production of the mycelium, which 

 completes the circle, the first half of which is formed by the vegeta- 

 tion and the second by the fructification. To sum up : a fungus re- 

 duced to its simplest form is composed of a septate or continuous 

 thread, terminated by a cell or nucleiferous swelling, which is the 

 spore. If we would follow in thought all the modifications of these 

 two organs, we may, by ascending constantly, as we have done, to- 



* Corda, Pracht. Flora, p. 50. 



