256 DIVISION II,—COURSE OF DEVELOPMENT OF FUNGI. 
are many gradations in the scale of arrestment and of perfection. Still it is more 
correct in such cases to speak not of arrest of development, but of different adapfatıon, 
or the metamorphosis of members, as we call foliage leaves, tendrils, and anthers in 
their various adaptations metamorphosed leaves or phyllomes, but do not call foliage- 
leaves rudimentary anthers, or anthers rudimentary foliage-leaves. At present we will 
keep to the correct and customary usage and apply the term rudimentary to those 
parts only which are arrested in respect to their development as members or 
structures, and also as regards their capacity in every respect for discharging their 
proper functions. 
There is still another phenomenon which is allied in many points to unusual 
metamorphosis and rudimentary development of members and yet is distinct from it, 
namely, the occurrence of organs which are well developed and capadle of performing 
their function, but which, as far as can be ascertained, are actually functionless. The 
phenomenon is of course rare; but the antheridia and archegonia of the apogamous 
Ferns! afford an example of its actual appearance among the organs of reproduction, 
which, from the facts recorded elsewhere, may be considered as beyond doubt. The 
occurrence therefore of this phenomenon must not be forgotten when we are-engaged 
in deciding about doubtful formations. 
The doubtful formations which we have to consider here are first of all the 
‘doubtful sporocarps’ of the Aspergilli (and Sterigmatocystis of Van Tieghem), 
and secondly most spermatia and spermogonia, The Aspergilli show exactly 
the course of development of Penicillium. The doubtful sporocarps (p. 206) 
are bodies that look like sclerotia and resemble the perithecia of Penicillium, but 
differ from these, according to some observers at least, in that they show no 
development of asci. Brefeld’s statements? to the contrary have been silently 
withdrawn or ignored by himself? since the appearance of Wilhelm’s profound treatise 
on the subject. The question then naturally arises, what was the reason for the 
negative results respecting the formation of asci which were all that were obtained 
during so many years? Brefeld answers the question by declaring these bodies to be 
‘rudimentary primordia of perithecia.’ This may be so with the bodies which 
Brefeld found in Aspergillus flavus and which he describes as undifferentiated tuber- 
like structures. But Wilhelm repeatedly obtained from A. flavus as well as from 
the other species a large number of well-developed bodies of the nature of sclerotia 
which in A. flavus had a black rind; the development therefore goes in this 
case also beyond the undifferentiated rudiment. 
These bodies in view of their structure can no more be called rudimentary 
than the sclerotia of Penicillium. The difference in structure which seems actually 
to be found in all cases, namely, that there are no distinct ascogenous hyphae 
such as appear in the sclerotia of Penicillium, cannot be of any importance, for this 
difference exists in like manner up to the commencing formation of asci between 
other primordial sporocarps, the perithecia of Claviceps and Pleospora for instance, on 
one side and those of Melanospora and others on the other. It may be allowed that 
these objections would be merely a playing with words, if there were sufficient grounds 

1 See above, p. 122. 2 Bot. Ztg. 1876, p. 265. v 
5 Schimmelpilze, IV, 134. 
