THE PERITHECIUM OF MELIOLA. 5 



When the hyphaa or branchlets of this fungus are looked upon from 

 above, and a strong light passes through from below, one often observes 

 a minute, circular, bright spot, which appears to shine through the 

 upper wall like a very small oil-drop ; on reversing the object, so 

 that the lower side of the hypha comes uppermost, this brilliant pore- 

 like spot appears much more evident, and is clearly due to a thinning 

 in the wall of the under side of the hypha, at a spot where no colouring 

 matter is deposited in the cell-walls, and where the contained proto- 

 plasm is placed more nearly in connection with the outside (see 

 figs. 7, 21, and 40). 



Bornet apparently refers to these bright spots when he speaks of 

 oily globules in the interior of the hyphee, 1 though he may have been 

 speaking of actual oil-drops developed in the dried specimens with 

 which he chiefly worked. If Bornet's remarks refer to the bright 

 spots here described, the facts of their appearing only on the lower 

 wall and not being altered by alcohol, &c, remain to be explained. 



Taking all the facts into account, the view seems to recommend 

 itself that these bright spots are the points of attachment of the hyphse 

 to the epidermis ; if so, they are to be regarded as haustoria of a very 

 rudimentary nature. The mycelium certainly is attached to the sur- 

 face of the leaf, though but feebly, and it appears suggestive that 

 alcohol specimens are more easily detached than fresh ones, possibly 

 because the protoplasm becomes contracted and rendered brittle. No 

 other anchoring bodies have been observed, and one notes that the 

 position of these brilliant spots accords with that of the well-developed 

 haustoria in Asterina 2 a genus of fungi at least allied to the Meliolas. 

 These bright points are not always present, and in some cases seem 

 to be normally absent. They are very generally formed at once 

 on germination, appearing on the first short tubes put forth by the 

 spore (fig. 40), a condition of things which may again be compared to 

 what occurs in Asterina, 5 and also in Erysiphe and allied forms. 4 Still 

 another point reminding us of Asterina and the Erysipheoz is the 

 function of the pyriform branchlets ; in some cases at least, they become 

 detached, and act as vegetative reproductive organs or conidia, each 

 putting forth bud-like processes which develop into new hyphee. 

 Bornet remarked the separation of these buds in Meliola ampliitricha, 



1 Op. cit., p. 260, and plate 21, fig. 3. 



2 See my description in Quar. Journ, Micr. Sc, October, 1882. 



3 Bornet, op. cit., plate 28, fig. 5. 



* De Bary, "Beitrage zur Morph. u. Phy3. d. Pilze," 1870, ser. iii., plate 12, figs. 1 and 2. 



