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Pycnides. They may be described in general terms as papillseform or 
wart-like bodies, generally black, — sometimes brown, — usually very 
minute,- — generally partially immersed in the thallus, on the surface 
of which they are scattered, — occupying a site similar to that of the 
spermogones. Indeed they differ essentially from spermogones only 
in containing corpuscles, called Stylospores , which are spore-like 
bodies, — sometimes septate, — usually oval or pyriform in shape, — 
but varying greatly both in form and size, with oily, distinct con- 
tents, always borne on the apices only of simple or unicellular, 
strongish sterigmata. 
10. As the essential difference between spermogones and pycnides 
lies in the characters of the contained corpuscles, and as their char- 
acters are of great importance, as bearing on the physiological func- 
tions of the said corpuscles, the comparison or contrast undernoted 
is made : — 
Spermatia. 
[representing Spermogones.] 
1. Structure solid, homogeneous. 
2. Always colourless. 
3. Of extreme tenuity : generally 
linear — of equal thickness through- 
out — straight or curved — never 
spherical. 
4. Of uniform size and shape. 
5. Exist in myriads. 
6. Absence of germinative power. 
7. No oil globules intermixed : em- 
bedded in a mucilage. 
8. Borne on the apices and sides of 
the sterigmata — on the apices when 
they are simple, on the apices and 
sides when articulated. 
Stylospores. 
[representing Pycnides.] 
1. Hollow : contents heteroge- 
neous— in part, at least, oily. 
2. Sometimes pale yellow. 
3. Vesicular: usually oval or py- 
riform. 
4. Varying more or less in size 
and shape. 
5. Greatly less abundant. 
6. Presence of germinative power. 
7. Oil globules generally inter- 
mixed. 
8. Borne on the apices only of 
sterigmata, which are always 
simple and stoutish. 
11. There is much more dubiety and difficulty regarding the na- 
ture of the pycnides and the functions of the stylospores than re- 
garding the nature and functions of the spermogones and spermatia. 
Two hypotheses have been advanced regarding the pycnides and 
stylospores, viz. — 
a. That they are substitutes for the spermogones and sperma- 
tia, — or in other words, a different form or type thereof. 
What lends probability to this view, is the perfect resem- 
blance to spermogones in outward appearance, site, &c. of 
