160 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
some definite stereometric relation, it should be intelligible in itself, it 
should be congruent with other related terms, it should be short, cor- 
rectly formed, and if possible pleasant, and, if an adjective, it should 
have a termination like that of related terms, e. g. those terms expressing 
position may end in al (or an), and those expressing direction in ad. 
All not quite irregular bodies may be grouped according as their 
middle is definable by a point, a line, or a plane. Thus, we have syn- 
stigma, svngramma, and sympeda. The stereometric ground-form of 
the synstigma is represented by a sphere or a regular endospheric 
polyhedron. Around the centre is the central or proximal region, the 
direction leading to it is centrad or proximad. So we have a distal region 
and distad direction. Position may be expressed by centran and distan. 
The syngramma may be an ellipsoid, a straight cylinder, a cone, or a 
spindle, &c. ; the line in relation to which all parts of the body are 
symmetrical is the principal axis, and at its end, if we follow a terminad 
direction, we reach there a terminan position. What lies in the principal 
axis is axian, directed towards it is axiad, away from it in a distad 
direction are distan positions. The plane of the principal axis is 
meridian, and parallel to this are parameridian planes. So we have 
transversan and paratransversan. The sympeda have three axes — two 
heteropolar and one isopolar ; of the heteropolar, one is the principal 
axis, the other dorso-ventral ; the isopolar axis is perlateral. All in 
the principal axis is axian ; its two ends are rostral and caudan. Re- 
lated terms are rostran and caudan, rostrad and caudad, dorsan and 
ventran, dorsad and ventrad. The two ends of the perlateral axis are 
dextral and sinistral, with dextran, sinistran, dextrad, and sinistrad as 
correlated terms. The author goes on to define the median plane sepa- 
rating dextral and sinistral, the frontal plane separating ventral and 
dorsal, and the transversal plane separating caudal and rostral. 
Theory of Sex.* — Messrs. J. A. Thomson and N. Wyld have made 
a critical review of recent contributions to the biology of sex, especially 
those of Ryder, Hartog, and Weismann. While accepting in the main 
the general theory stated in ‘ The Evolution of Sex ’ by Geddes and 
Thomson, the authors advocate the following amendment: — “In con- 
trasting the sexes or their reproductive elements, the contrast must be 
expressed in ratios ; the storage of potential energy in a female need not 
be absolutely greater than in the corresponding male, but in the female 
the ratio of anabolic to katabolic processes is greater than the corre- 
sponding vital ratio in the male. In the great majority of cases, of the 
food assimilated and stored by a male the greater amount is used, after 
growth has ceased, for movement and general functions, the reproductive 
function making relatively small demands on the nutritive store ; while 
in the female organism a relatively great amount is used for the forma- 
tion of ova or for the nutrition of the embryo. The female organism is 
one in which the general ratio of anabolism to katabolism (the mean of 
many ratios) is greater than the corresponding general ratio in the male.” 
Evolution of Sex.f — Dr. C. J. Wynaendts Francken seems to believe 
that the male organism inclines to greater activity, the female to greater 
* Proc. R. Phys. Soc. Edin., xi. (1891-2) pp. 249-82. 
f Tijdschr. Nederland. Dierk. Ver., iii. (1892) pp. 206-225. 
