GERMINATION AND GROWTH. 159 



Another method of reproduction, not uncommon in Mucorini, 

 is described by Van Tieghem in this species. Conjugating 

 threads on the substratum by degrees elaborate zygospores, but 

 these, contrary to the mode in other species, are surrounded by 

 curious branched processes which emanate from the arcuate cells 

 on either side of the newly-developed zygospore. This system 

 of reproduction is again noticed more in detail in the chapter 

 on polymorphism. 



M. de Seynes has given the details of his examination of the 

 sporidia of Morchella esculenta during germination.* A number 

 of these sporidia, placed in water in the morning, presented, at 

 nine o'clock of the same evening, a sprout from one of the 

 extremities, measuring half the length of the spore. In the 

 morning of the next day this sprout had augmented, and 

 become a filament three or four times as long. The next day 

 these elongated filaments exhibited some transverse divisions 

 and some ramifications. On the third day, the germination 

 being more advanced, many more of the sporidia were as com- 

 pletely changed, and presented, in consequence of the elongation, 

 the appearance of a cylindrical ruffle, the cellular prolongations 

 arising from the germination having a tendency towards one of 

 the extremities of the longer axis of the sporidium, and more 

 often to the two opposed extremities, either simultaneously or 

 successively. Out of many hundreds of sporidia examined 

 during germination, he had only seen a very few exceptions to 

 this rule, among which he had encountered the centrifugal 

 tendency to vegetate by two opposed filaments, proving that if 

 it bears a second by the side of the primal filament situated at 

 one of the poles, a second would also be seen from the side of 

 the filament coming from the opposite pole. 



Before being submitted to the action of water, the contents 

 of the sporidia seemed formed of two distinct parts, one big 

 drop of yellow oil of the same form as the sporidium, with 

 the space between it and the cell wall occupied by a clear liquid, 

 more fluid and less refractive, nearly colourless, or at times 

 slightly roseate. As the membrane absorbed the water by 



* Seynes, " Essai d'une Flore Mynologique.' - 



