76 MARION HINES 
demonstrated his preparations without a dissenting voice. Those 
preparations consisted of three embryos, a 13.6 mm., a three 
months fetus of 50 mm. C. R., and a model of a 19.4 mm. C. R. 
There was no fissura arcuata in any of these specimens. How- 
ever, he noted in well-preserved brains, two to four months old, 
‘a slight trough-like invagination of the medial hemisphere 
wall” (p. 31), but could not identify an arched fissure. More- 
over, in speaking of a sixteen-week embryo (p. 33), he says that 
he can find no trace of the posterior arched fissure, but that the 
primordium of the pes hippocampi is visible, not as an infolding 
of the brain wall, but rather as a thickening at that point. 
At this meeting Schaper demonstrated the fissureless condi- 
tion of the medial wall in the two embryos 10.5 cm. and 4.6 em. 
Further, he pointed out an insignificant invagination in the 
region of His’ anterior arched fissure in the Hochstetter fetus 
of 49 mm. ‘The discussion must have attained some warmth or 
Fick would not have advised that the term fissure be stricken 
out of embryological terminology. It is difficult to imagine the 
necessity of calming a morphologist. . 
Goldstein (’04) described upon the smooth surface of the me- 
dial wall ‘“‘at the point where the anterior arcuate fissure should 
be sought, a well defined sulcus which extends approximately 
vertically from the insertion of the olfactory bulb and which 
His considers the equivalent of his ‘Bogenfurche’”’ (p. 581). This 
is the fissura prima, and not the true fissura arcuata. For him, 
the ventricular aspect of the cortex is little disturbed. The 
broadening and deepening is not an expression of an infolding, 
but rather a condition of nervous differentiation of the outer 
level (p. 582). Comparing the posterior arched fissure or the 
fissura hippocampi with His’ figure 86, he says that the fissure 
is not as deep as that of His; the outer cortex describes only an 
arched line so that a slight indentation can be seen (p. 586). 
In 1901 J. Symington reported at a meeting of the British 
Association for the Advancement of Science that the frequency 
and depth of the temporary fissures had been exaggerated, but 
that they occurred in well-preserved material. Although the 
arcuate fissure was not a product of fixation, it could have no 
