2 I 8 
The Ohio Naturalist. 
[Vol. II, No. 5, 
cases as the Pine the tissue which surrounds the embryo can be 
called what it actually is, the female thallus or female gametophyte 
filled with food material. 
The term root must be restricted to the sporophyte generation 
and root-hairs to hairs on real roots. The terms rhizoid and hold- 
fast may be used for similar organs of the gametophyte. The 
word leaf should be restricted entirely to the sporopyte. Any 
reduced leaf may be called a bract or scale-leaf. For expansions 
on the gametophyte the term scale may be used as moss scale, 
liverwort scale, scaly Liverworts, etc. Expanded thalli, as those 
in many of the red and brown Algae, and Liverworts and Mosses 
may be called fronds. There is no need of calling a fern leaf a 
frond. It is of the same nature as the leaf of a seed plant and 
should have the same terminology. The term stoma should be 
used only for true stomata on the sporophyte. Passages of some- 
what similar function, but not similar structure on the gameto- 
phyte of some Liverworts may be called air passages for want of 
a better term. It would be well to drop the term prothallus in 
the Pteridopliytes and call the gametophyte, what it really is, 
simply a thallus. The term germinate should be restricted to 
the division or budding of cells and spores ; it should not be used 
for the breaking out of the embryo plant from the seed. This 
process should always be called sprouting. There is not even an 
analogy between this process and the germination of the spore. 
The terms photosynthesis, digestion, respiration, and assimila- 
tion should be properly applied, especially assimilation, which 
should refer only to the conversion of dead food materials into 
living protoplasm. It would be very fortunate if the terms 
daughter cell, mother cell, and grandmother cell would always be 
applied to successive generations of cells produced by division. 
Thus in the formation of the spores on the sporophyte, the cells 
which are differentiated and usually separated from the general 
tissue are spore grandmother cells. These divide into two to 
form the two spore mother cells, which again divide, thus form- 
ing the four daughter cells which develop into the spores. These 
grandmother cells are usually called spore mother cells, but it is 
better to use the term sporocyte, and if there are two kinds of 
spores, the cells may be called microsporocytes and mega- 
sporocvtes. 
These are only a few of the most important terms that might 
be defined, but if these alone were always correctly applied, 
amateur students as well as those more advanced might obtain a 
clearer conception of the subject with much less outlay of misdi- 
rected effort. 
