52 DIVISION I. GENERAL MORPHOLOGY. 



hyphae destined from the first for the particular structure. In small compound 

 sporophores with an apex which continues narrow, being composed of only a few 

 hyphae, like those of Typhula to be noticed presently, it may, though it need not 

 necessarily, be assumed that such is the case. In the much more frequent cases in 

 which the advancing apex or margin becomes constantly broader with uniform 

 thickness and separation of its elements, new hyphal branches must be introduced 

 one after another between the original ones, or take the place of them in sympodial 

 succession. In long-lived species with periodical cessation of growth in the cold or dry 

 season most of the extremities of the branches must die away, and be replaced when 

 growth begins again by branches of deeper origin which thrust themselves between 

 them. The position of the dead extremities or the portions of new growth limited by 

 them may then be seen as zones in the older structure. 



The consideration of special phenomena of development is deferred to a later 

 page for the reasons assigned above. But it will be well to give a more detailed 

 description in this place of some examples at least of progressively growing compound 

 sporophores, because this mode of growth is very general both in the different 

 divisions of the Fungi and in sporophores of very different morphological value. 

 The examples are for the most part those of the first edition of this book. 



1. The stalk-like compound sporophores of Typhulae which form sclerotia, 

 Typhula variabilis especially, begin on the sclerotium as the bundle of firmly united 

 parallel hyphae with their extremities curving dome-like towards each other, which 

 was noticed above on page 38. The compound sporophore increases in length. The 

 united extremities of the hyphae in the dome-shaped apex continue all the while 

 very delicate and full of protoplasm, and comparatively small-celled. As the 

 segments of the hyphae are further removed from the apex of the growing sporophore 

 they increase steadily over a certain distance in length, breadth, and thickness, and 

 the whole structure increases in compactness and firmness ; no further augmentation 

 takes place at its base. From these facts it appears that the growth in length of 

 the sporophore, so far as it depends on formation of new cells, takes place at and 

 close beneath the apex by the apical growth of the united hyphae ; this is therefore 

 the growing point. Then the cells produced at the growing point elongate in the 

 order in which they are formed and assume their ultimate form. As the elongation 

 commences the primordia of scattered unicellular hairs make their appearance as 

 branches on the superficial hyphae of the lower sterile portion, and on the upper part 

 the dense weft of the hymenial layer. At length the activity of the growing point 

 ceases and with it the growth of the whole sporophore. In the interior of the 

 parts more remote from the growing point there appears to be no further formation, 

 or at any rate no considerable formation of new cells, either by division of previously 

 formed cells or by addition of new hyphal branches introduced between those already 

 in existence 1 . 



2. The compound sporophores of Sclerotinia Sclerotiorum (Fig. 22), the early 

 stages and special structure of which will be again described in Division II, burst forth 

 as cylindrical bodies from the sclerotium, grow in this form to a length of 10 mm. 

 more or less, and then increase in breadth at the apex in such a manner as to pass 

 through the shape of a club into that of a stalked funnel-shaped cup, which may 

 finally have its margin turned outwards. The young cylinder consists chiefly of a bundle 

 of nearly parallel hyphae ; the slender delicate-walled extremities of the hyphae 



1 .See also Brefeld, Schimmelpilze, III. Reinke u. Berthold, Die Zersetznng d. KartofTel clurch 

 Pilze, p. 58. 



