180 
Journal of Mycology 
[Vol. 10 
advantage, its results would be a positive gain to the race; it 
would therefore likely be perpetuated and the process become (by 
“selection”) fixed and common. The fact that in some plants 
fusion of “swarm spores” is the rule, and that in the higher plants 
the gametes are brought together by aid of highly .specialized 
structures suggests the correctness of this interpretation of the 
origin, and at the same time is probable proof of the advantages 
of sexual union. 
View Points in Science. — The countless multitudes of 
plants and the endless variety in form and structure baffles an 
adequate comprehension of the Vegetable Kingdom. To under¬ 
stand, even in a general way, our common herbs, shrubs, and 
trees, we need to know their gross and minute structure, the rela¬ 
tion and derivation of the organs and other specialized structures, 
their mode of living or physical and chemical energies displayed 
in growth, their relation to the environment in which they live, 
their reaction when untoward exigencies arise, their individual 
and their race development. Any one of these several View 
Points may for a time be made prominent; and a mass of knowl¬ 
edge — often more or less crude and quite insufficient — has 
already accumulated relative to each, and for which a technical 
designation is employed. Naturally the first phase to engage 
attention is the mere external form, and examination of the parts 
or organs presented — hence the term Gross Anatomy. With the 
aid of a microscope the minute anatomy can be determined satis¬ 
factorily so far as this instrument is able to reveal it. The masses 
of various kinds of material of which the organism is composed 
are called tissues; therefore the word Histology is used — the 
Greek word histos meaning tissue. But the various kinds of tis¬ 
sue in the plant-body and the organs presented may be studied 
with reference to their origin and mode of differentiation, and 
especially as to their fundamental relationship,— such a study is 
called Morphology. It includes an examination of the tissues and 
organs in the act of development and differentiation. It should 
therefore give us a correct interpretation of the parts of a plant 
and a clue to its meaning as a whole. When this developmental 
history is traced from the egg and carried through the remarka¬ 
ble changes in the early stages it is called Embryology. Struct¬ 
ures that in the adult or mature form may be quite different in 
appearance or function may have been derived from the same, 
i. e. fundamentally corresponding, parts of the organism; they 
would then be said to be homologous. Thus the floral leaf — e. g. 
the stamen — is homologous with the foliage leaf; the panicle — 
e. g. the head of oats — is homologous with the Sunflower; the 
Fern leaves with their sporangia (“fruit”) are homologous with 
the stamen and pistil in the Rose; the spore in the Lower plants 
is homologous with the cell from which the embryo in the seed 
of the higher plants develops. Homology — as this phase of 
