PYCNIDES OF CRUSTACEOUS LICHENS. 203 
Il. Difference*. 
1. The form of pycnides is much more frequently point-like or papilloid than in 
spermogones. 
2. Their size is generally much more minute. 
3. Their colour is much more frequently black; and there is a much less variety of 
colour. 
4. Their ostiole is much less frequently apparent. 
5. Their cavity is almost always simple. 
6. Oil-globules, which are of frequent occurrence, associated with or contained in 
stylospores, are never associated with or contained in spermatia. 
7. Stylospores are frequently septate, or they contain nuclei or granular matter; 
while septa, nuclei, and granularity, are almost unknown in spermatia. 
8. Stylospores are frequently coloured ; while colour is most unusual in spermatia. 
. 9. Stylospores are much more irregular in form in the same individual than 
spermatia. 
In the nomenclature of spermogones and pyenides, spermatia and stylopores, licheno- 
logists have been in the habit of reasoning in a vicious circle. A theoretical standard of 
distinction is established from a limited experience of a very few, and perhaps very diverse, 
forms of these organs. According as a newly discovered organ or its corpuscles cor- 
respond to the one group of characters or the other, it is called a spermogone or pycnide, 
and the corpuscles, spermatia, or stylospores. And then, having so denominated them, 
we proceed to speak of the resemblances and differences. We assume the differences to 
be radical, relating no less to function than to anatomy and morphology. But every 
addition to research into the microscopic anatomy of the organs in question brings to 
light more numerous points of resemblance, and more frequent exceptions to the points 
of difference. And the time perhaps approaches when a revision of their nomenclature 
will become necessary ; when the present faulty nomenclature will be superseded by one 
that is more comprehensive, and at the same time more scientific, in accord with fact— 
that is—apart from speculation ! 
Arguments have been generally drawn, from the position and period of development of 
the spermogones relative to the apothecia, in favour of the supposed fertilizing influence 
of the contents of the former on those of the latter. But it has to be borne in mind 
that, while many lichens are monecious, containing both spermogones and apothecia on 
the same plant or thallus, and while this may be considered theoretically their normal 
condition, many others have these organs on separate plants or thalli, and some have 
no apothecia or no spermogones. Moreover, whatever can be said of the site of the 
spermogones in relation to the apothecia may be equally said of the pyenides, whose 
function, nevertheless, is supposed to have no connexion either with apothecia or sper- 
mogones! In regard to the relative periods of development of spermogones aná apo- 
thecia, it may be true, as authors have asserted, that the former appear earlier than the 
* The distinctions—real or supposed —between stylospores and spermatia, basidia and sterigmata, are more fully 
set forth in my paper on ** Polymorphism," p. 4. 
