224 On a second membrane 



same time very contractile, so that when yet in situ, it frequently 

 becomes nodulose from the pressure of the sporidia, especially if 

 they get out of their natural position, which is mostly, though not 

 universally, with their major axis parallel to the asci. The portion 

 which projects after the asci are fractured, if empty, is generally 

 contracted to a mere thread. In several instances, when the outer 

 tube has been snapped asunder, I have seen a large portion of the 

 inner tube projecting, and in one case it still retained three sporidia. 

 Similar appearances presented themselves in Sph. pedunculata, but, 

 from the circumstance of the sporidia being enveloped in a pellucid 

 mucus, the structure is not always easily made out. The secondary 

 membrane in general adheres very closely to the sporidia, adapting 

 itself to their form, so that the row of sporidia when not as yet dis- 

 arranged presents a moniliform articulated thread ; the dark appa- 

 rent articulations arising probably from the mutual pressure of the 

 sporidia with their mucous coats against each other. Indeed, from 

 the manner in which the sporidia adhere together when the asci are 

 ruptured, I am inclined to think that the secondary membrane is 

 in the present species so extensible, as to form a close covering to 

 the sporidia, however much they may be disarranged. This is not, 

 however, always the case, as the secondary membrane is sometimes 

 perfectly distinct, both before and after the rupture of the asci. 

 This I have seen especially in a remarkable variety, or rather form 

 of the species, in which the receptacle is reduced almost to nothing, 

 and the perithecium solitary. Besides the curious circumstance of 

 the sporidia being coated with mucilage, a circumstance, as far as 

 I know, without parallel in the genus, it is remarkable that they 

 have another equally distinguishing feature, which is the existence 

 of a regular longitudinal depression on one side, so as to resemble 

 very strongly such pollen grains as have a single band. This is 

 best seen when they are divested of their mucilaginous coat, which 

 appears to be uniformly the case before they are discharged. It is 

 by no means common amongst the uterine Fungi to have any ine- 

 qualities in the coat of the sporidia, except such as are septate. At 

 present I recollect but a single instance in the genus Ascobolus, in 

 which I have seen them very strongly wrinkled. They vary remar- 

 kably in form, as will be seen from the accompanying figures, and in 

 some specimens which, in addition to the usual coating of earth, 

 had penetrated through a layer of cow- dung, it is most curious, in 

 consequence, I suppose, of excessive nourishment, the sporidia were 

 uniformly more than twice the ordinary size. 



The primary membrane, though sometimes rather rigid, is by no 



