240 



DIVISION II.— COURSE OF DEVELOPMENT OF FUNGI. 



Section LXIX. 3. Spermatia, spermogonia. Organs in every respect ex- 

 tremely like those which are thus named in Collema, Physrna, &c. (page 211) are found 

 in almost all the rest of the Lichen-forming Ascomycctes ; the genus Solorina may be 

 mentioned as an exception among those in which this point has been carefully 

 examined. These organs occur also in many species which do not form Lichens 

 both among the Discomycetes and especially among the Pyrenomycetes. On the 

 ground of these points of resemblance the organs in question are entitled to the 

 names given to the corresponding organs of the Collemeae and Polystigma, and are at 

 least to be regarded as homologous with them. 



All these organs agree first of all in the formation of spermatia, small ellipsoid, 

 or more commonly narrowly rod-shaped, bodies, which are often also bent, as in 

 Rhytisma, Diatrype (Fig. 114), and Polystigma. Their absolute size varies much in 

 the different species ; those that have the form of narrow rods are according to 

 Tulasne 6 or 7 // in length in species of Diatrype, and as much as 30 \i in Polystigma 

 rubrum, or less than 6 \i in some species of Gyrophora (Fig. 100); the ellipsoid 

 spermatia of Peltigera have a length of 12-22 \i. Their structure, as far as it can be 

 ascertained, is similar to that of very small and delicate spores with homogeneous 



FIG. 112. Valsanivea,Tv\. Vertical section through 

 a stroma ; in the centre a spermogonium ejecting sper- 

 matia ; on each side a perithecium. After Tulasne. 

 Slightly magnified. 



FIG. 113. Tympanis coiispersn, Fr. Aa 

 shortly stalked apothecium with two spermo- 

 gonia at its base, in median longitudinal 

 section. Spermatia are escaping from the 

 spermogonium to the right. After Tulasne. 

 Slightly magnified. 



protoplasm, and they are formed in the same way as acrogenously produced spores, 

 being abjointed singly or in rows from short and narrow ends of filaments (sterigmata, 

 basidia) ; the latter organs vary in the different species and genera, being either 

 elongated and cylindrical, unsegmented or with indistinct septa, and forming spermatia 

 at their apex only (sterigmata in the narrower sense of Nylander), or they are manv- 

 membered cell-rows in which the cells are little longer than broad, and form each of 

 them lateral spermatia close to their upper end (Fig. 100 B, the arthrosterigmata of 

 Nylander). This latter form has been chiefly, if not exclusively, observed in certain 

 genera of Lichen-fungi. 



These spermatia are always formed side by side in large numbers, and are 

 imbedded, as in Collema, in a jelly which becomes hard and brittle as it dries, and 

 dissolves and disappears in a super-abundance of water. U they are placed with the 

 jelly in a comparatively large quantity of water, they exhibit a gently tremulous 

 oscillating movement ; but since this movement appears in spermatia which have 

 been killed by boiling or by being treated with absolute alcohol as well as in those 

 which are alive and fresh, it must be considered to be a purely physical phenomenon 

 due to the motion which is caused in the water by the swelling and partial dissolution 



