192 
Spermogones or Pycnides—to form, 
DR. LINDSAY ON THE SPERMOGONES AND 
size, colour, site, number and distribution. 
Variation is apparently greater in spermogones than in pyenides; but it must be 
borne in mind that the former organs are much more frequent than the latter in 
the great majority of lichens, both higher and lower. 
(a) Sterigmata—to form, size, simplicity, and ramosity. 
(b) Spermatia—to form and size. 
(c) Basidia—to length. 
(d) Stylospores—to form, size, contents, or ii A as number of septa or nuclei, 
or the amount of oily or granular matter.) 
Plurality, on the.other hand, relates e. y. to the occurrence of more than one distinct 
form of spermogone or pycnide; or of spermogones in addition to pycnides; or pyenides 
besides spermogones; or of more than one form of both spermogone and pyenide. The 
respective phenomena of Polymorphism and Plurality will, however, be more readily 
understood by the following illustrations :— 
I. Polymorphism. 
1. Different forms or sizes of sterigmata or spermatia in same species :— 
Ex. Opegrapha vulgata, nos. 4, 5, 7, 8, 20. 
(1st Mem. p. 141.) 
Graphis scripta, no. 2. 
anguina, no. 1. 
Arthonia cinereo-pruinosa. 
impolita, no. 4. 
ilicina, no. 1. 
Stigmatidium crassum, nos. 3, 4. 
Mycoporum elabens. 
Verrucaria epidermidis, nos. 1, 3. 
Calicium roscidum, no. 1. 
trachelinum, no. 2. 
tigillare. 
Lecanora varia, nos. 3, 6, 9. 
Lecidea parasema, nos. 1, 9, 10, 11, 18. 
contigua, nos. 1, 4, 5, 10, 11. 
abietina, nos. 11, 12. 
—— sanguinaria, nos. 1, 5. 
Ex. Lecidea Ehrhartiana, nos. 1, 2, 5. 
decolorans, no. 2. 
——— flexuosa. 
— ina. 
—— Griffithii, nos. 1, 5. 
synothea, no. 2. 
-—— quernea, no. 2. 
pineti. 
Pertusaria pustulata. 
Lecanora atra, nos. 5, 6, 7. 
subfusca, nos. 12, 15, 17. 
—— — milvina, no. 2. 
Verrucaria glabrata. (Observations on 
New-Zealand Lichens, p. 554, pl. xiii. 
f. 30, a, 5.) 
In some of the foregoing instances, the differenees in form or size of the sterigmata 
or spermatia are such that the organs containing them may be regarded as themselves 
essentially different, in which case they belong rather to the category of Plurality of 
organs. Indeed, though I have instituted a distinction between polymorphism and plu- 
rality, they are inseparably connected. The distinction is one of convenience only, arti- 
ficial and arbitrary, but not more so than the lines of separation or demarcation esta- 
blished by systematists usually are. 
