CHAPTER HI. — SPORES OF FUXGT. 103 



confluens, Reess 1 , have a broad gelatinous envelope round their large compound 

 spore-mass. The spore-heads in Acrostalagmus and the heads of Myriocephalum 

 botryosporum composed of crowded branching spore-chains are enclosed in a 

 gelatinous envelope, and many other instances of the kind might be mentioned. To 

 this place also belongs the apparently homogeneous often very soluble gelatinous 

 substance which covers the gonidial layers in a great number of Ascomycetes, and 

 in which their spores are imbedded. See above on page 70. 



The morphological significance of the different appendages has still to be deter- 

 mined more exactly by the history of development. The gelatinous coatings and 

 large gelatinous envelopes of entire hymenia must in the case of acrogenously produced 

 spores be the gelatinous outer membranes of spores or spore-mother-cells, or the product 

 of their coalescence. In the case of many spores produced in asci it is a priori probable 

 that the appendages and gelatinous envelopes are also partial thickenings of the 

 outermost lamellae of the membranes, or are due to the gelatinous character of the 

 whole of the outer layer. This would be in accordance with Sollman's statements 2 , 

 but the confusion that reigns in them with regard to the most elementary principles of 

 histology makes it impossible to trust them. The sac which encloses the spores of 

 Sphaeria Scirpi is certainly the primary outermost lamella of the membrane which at 

 first fits everywhere closely to the spore, and becomes expanded into the conical 

 appendages at the extremities of the spore as it ripens. Zopf 3 maintains that such 

 gelatinous appendages, -especially in the Sordarieae, are portions of protoplasm 

 which have not been used in the formation of spores, that is, speaking plainly, are the 

 direct product of the protoplasm in the ascus which was not devoted to the spore- 

 primordia. This view is not altogether new, for Kiitzing * before ascribed a similar 

 origin to the entire episporium of Tuber ; but it deserves consideration both as regards 

 the gelatinous appendages and as regards the episporium as a whole, especially 

 considering the analogy of the development of the oospores of Peronospora (Chapter 

 V) ; it has not, however, been distinctly proved. 



Appendages of a different origin from these gelatinous ones are peculiar to the 

 ascospores of Sordaria fimiseda, S. coprophila, and others, and may even occur along 

 with them 5 . The spores of the first of these two species are in their early stages small 

 delicate ovoid cells prolonged below into a cylindrical stalk and rich in protoplasm. As 

 all its parts increase steadily in size, soft gelatinous thickening of its membrane with fine 

 longitudinal striation makes its appearance at both extremities of the spore, projecting 

 outwards in the form of a sharply conical usually hooked process, and growing in size 

 as the spore grows. When the spore has attained its full development the greater 

 part of the protoplasm moves from its lower cylindrical into the upper ovoid portion, 

 which is then divided off from the former by a transverse wall, while its membrane 

 becomes thickened and stratified, and gradually acquires a dark violet colour ; the 

 cylindrical portion continues attached as a hyaline stalk to the dark spore (Fig. 52). 

 As appendages of this kind arising from sterile sister or neighbour cells may be 



1 See Tulasne, Carp. — Fresenius, Beitr. 



2 Bot. Ztg. 1862 and 1863. 



3 Sitzungsber. d. Naturf. Freunde, Berlin, Feb. 17, 1880. 



4 Philosoph. Bot. p. 236. 



5 Woronin, Beitr. III. — Winter, Die deutsclien Sordaricn, Halle, 1873. 



