522 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Intercellular Connections in Notochord Tissue.* * * § — Herr F. K. 
Studnicka finds considerable variety in the notochord-cells of Verte- 
brates, and directs attention to the very marked occurrence of intercellular 
bridges in Esox lucius , Belone acus, Syngnathus, &c. The intercellular 
spaces are crossed by a large number of plasmic bridges, producing an 
appearance like that of a layer of small vacuoles round the margins of 
the cells. In the middle of each of the delicate connections there is a 
node which stains intensely with hmmatoxylin. Similar nodes have been 
observed in the intercellular connections in plants. 
c. General. 
Measure of Variability.! — Mr. E. T. Brewster has followed Quete- 
let, Stieda, Galton, Weldon, and others in applying the statistical 
method of estimating probable error as a measure of variability. His 
subject-matter (taken at random) relates to body-measurements in man* 
skull-measurements of two species of Lepus , body-measurements of 
Zapus insignis, Z. hudsonius, and Sitomys americanus , and skull-measure- 
ments of cat, fox, and lynx. His thesis is stated in the following 
words : — “ While it is generally agreed that specific characters are more 
subject to striking variations in individuals than are the characters 
common to allied species , it is not clear how far this relation ex- 
tends. I wish to show that what is true of obvious variations and 
sports is also true of those minute differences between individuals which 
only careful measurements can detect ; or, in other words, that measurable 
quality is, in general, variable in individuals in proportion as it is a 
distinguishing character of the group to which the individuals belong. 
. . . The conclusion is, that there is so intimate a causal connection 
between the characters of individuals and those of the allied groups into 
which they are combined, that, in proportion as any character is variable- 
in the individuals of one group, it is different in the allied groups.” 
Variations in Spinal Nerves of Hyla. — Miss G. Sweet J has made an 
elaborate study of the variations in the spinal nerves of Hyla aurea , the 
common green frog of Victoria. She finds a forward homoeosis in the 
sacral plexus, and a backward homoeosis in the brachial plexus. There 
is a tendency in this form, as in some other Anura, towards a concentra- 
tion of the origin and functions of the spinal nerves towards the central 
region of the body. 
Dr. H. Adolphi § has already reached the same general conclusion, 
and confirms it in a third contribution dealing with Bufo cinereus. 
Schneid. 
Muscular Variations in Primates. || — Dr. J. H. F. Kohlbrugge has 
devoted seven years to a study of the musculature and peripheral nerves 
of Primates, especially of the Semnopithecini. This study has its im- 
portance for the comparative anatomist and the anthropologist ; but we 
notice it here because the author directs particular attention to the? 
* Zool. Anzeig., xx. (1897) pp. 286-8 (1 fig.) (to be continued). 
t Proc. Amer. Acad., xxxii. (1897) pp. 269-80. 
X Proc. Roy. Soc. Victoria, ix. (1897) pp. 264-96 (many tables) 1 . 
§ Morph. Jahrb., xxv. (1896) pp. 115-42 (1 pi.). 
U Verb. K. Akad. Amsterdam, v. (1897) No. 6, 246 pp. 
