ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
607 
formula C 12 H 24 N 6 0 3 ,H 2 S0 4 . Its disruption-products yielded several 
bases, of which two were obtained pure, viz. Arginin (which Schulze and 
Steiger obtained in seedlings of Lupine), and a second, which he names 
Histidin. Sturin differs from all known proteid-like substances in 
yielding on disruption little or no trace of monamidic acids. It is 
characteristic of these protamin substances that they tend to unite with 
proteids, holding these in chemical combination. 
Cell-Membrane.* — Prof. F. E. Schulze points out that the term 
“ cell-membrane ” is used too vaguely and loosely. He proposes that 
the term should be used for any connected membranous peripheral layer 
which is distinctly marked off from the plasma of the cell. If the 
membrane encloses the cell on all sides, it is a pellicle ; if it lies only 
on the free surface, it is a cuticle. A crust, on the other hand, is a 
coarse marginal layer of the cell passing gradually into the soft plasma. 
Intercellular Union of Epithelial Cells.f — Prof. F. E. Schulze dis- 
cusses with his wonted clearness the question of intercellular connections. 
He begins with an historical sketch. When epithelial cells were thought 
of as surrounded by firm membranes, it was naturally supposed that they 
were held together by an intercellular cementing substance. In 1863, 
0. Schronn demonstrated the pore-canals in the membranes of the cells 
forming the rete Malpighii. In 1864, Max Schultze described the inter- 
locking processes which hold epithelial cells together. But Bizzozero 
and many others showed that the processes meet but do not interlock. 
The notion of plasmic bridges was supported by many, while others — • 
e.g. Manille Ide, held the connecting strands to be derivatives of the 
primary cell-membrane. The general result has been the recognition 
that epithelial cells are connected by numerous strands, between which 
there is an intercellular canalicular system filled by a lymph-like fluid. 
Prof. Schulze has studied the epidermis of young amphibian larvae 
under high magnification, and has formed conclusions somewhat different 
from those usually expressed. Even with immersion-lenses, the larvae 
of tree-frog, newt, &c„ may be observed in their living state. In all 
cases the epidermis consists essentially of two layers of rather large 
cells ; the outer with cuticular fringe, the inner apposed to the cutis. 
Between two neighbour-cells there is a layer of vacuoles, filled with 
lymph-like fluid, and separated by a bridging netw r ork connecting the 
cells. To begin with, the young membraneless cells are united by a 
refractive hyaline layer; in this marginal layer vacuoles appear in 
increasing number and size, and thus give rise to the intercellular 
network. 
Structure of Nerve-Cells. } — Herr M. von Lenhossek says that some 
of the discrepancies between his results and those of Flemming, especially 
as to the arrangement of the basophilous granules, are due to the differ- 
ences in the objects observed. But as to the structure of the ground- 
substance in the spinal ganglion cells of Mammals, Lenhossek finds, as 
before, that this is a fine granular honeycomb, and not fibrillar. 
The basophilous granules are too regular in disposition to be pre- 
* Verh. Anat. Ges. X. Anat. Anzeig. Erg.-Heft., xii. pp. 27-32. 
t SB. K. Preuss. Akad., 1896, pp. 971-83 (I pi.), 
j Verh; Auat. Ges. X. Anat. Anzeig. Erg.-Heft, xii. (1896) pp. 15-21. 
