CERTAIN SPECIES OF Mucor 305 
along the principal sporangiophore and never surpass it. This 
group comprises the species usually little branched.” The 
Cymo-Mucor group is defined by him thus: ‘‘There is formed below 
the terminal sporangium a second branch surpassing the first, 
then on this second there arises a third which surpasses the 
second. The insertion of the ramifications is usually alternating; 
as a result there is produced a very characteristic zig-zag ap- 
pearance.’’ Hagem gives no explanation of his use of these terms, 
but it appears from his figures and descriptions that in some cases 
he departs from the usage of past writers. For example, he 
classifies Mucor sphaerosporus and M. griseo-cyanus as racemosely 
branched, although his figures show that Lendner follows past 
usage in referring them to the cymose group of Mucor. Thus we 
have confusion arising from opposing conceptions of terms. It 
will be necessary to consider the terms applied to branching. 
According to Sachs (1874), De Bary (1887), Schneider (1905), 
and Strasburger (1912) the two kinds of branching are monopodial 
and dichotomous; Jost (1907), on the contrary, uses the terms 
lateral branching and dichotomy. As we are not concerned with 
the latter we shall consider only the monopodium. 
In the monopodium there is present a central axis with a grow- 
ing point at its apex containing the apical cell. Branching in the 
monopodium, unlike the process in the dichotomy where a division 
of the apical cell results in a forking of the main axis, takes place 
by the development of axillary buds situated near or at some dis- 
tance from the growing point of the stem. These lateral branches 
develop by the growth of apical cells. When the lateral branches 
remain shorter than the persistent main axis a racemose type of 
branching is evident. When, on the contrary, one or more lateral 
branches exceed the main axis, sometimes even assuming a 
central position, a cymose system of branching results. See Sachs 
(1874, p. 183). This applies in general to the higher plants. 
According to Brefeld (1872), the germination of a spore of 
Mucor Mucedo, which may be regarded as typical for the genus, 
takes place in the following manner: the spore swells and there are 
produced one or several germ tubes which grow very rapidly and 
soon begin to branch in all directions, so that an irregularly 
much-branched thallus is produced. It should be noted that there 
