JO4 



DIVISION I. GENERAL MORPHOLOGY. 



mentioned also the envelope-cells on the spore-clusters of Urocystis, which will be 

 described in Chapter V, but not the germ-tubes which appear inside the ascus 

 in Sphaeria praecox, and which were described by Tulasne 1 as filiform appendages. ' 

 We have already spoken, in concurrence with ZopPs views, of the physiological 

 import of the gelatinous appendages as organs which may serve to attach the asco- 

 spores to one another and to the apex of the expanding ascus. This is evident 

 in the case of the Sordarieae, in which the spores, each with its dark episporium, lie in 

 a row in the ascus one behind the other and in contact with one another, and the 

 conical gelatinous processes on each spore are firmly attached to those of its next 



FIG. 52. Sordariafimifeda, de Not. Development of the spores, the successive stages in the order of the letters, a -J 

 from recently isolated uninjured asci ; / a fully developed spore but with the yellowish brown membrane still transparent and 

 the germ-pore visible above, g a ripe spore escaped from the ascus, with its membrane of a violet black colour. Magn. 390 

 times. 



neighbour or are twisted round them. How far the function of these appendages is 

 the same in other cases is a question which requires further careful investigation. 



Of the chemical nature of the spore-membrane only some isolated facts are known, 

 and the subject is still in need of more thorough examination. Hoffmann 2 has 

 collected together a variety of details on this subject. 



Most spore-membranes, according to the concurrent testimony of all observers, 

 are distinguished by their great power of resisting decomposition and the influence of 

 strong reagents, more especially concentrated mineral acids. Many are only slightly 



Carp. I p. 80. 



Pringsbcim's Jahrb. II, p. 308. 



