496 A. B. DAWSON 
The literature on this subject has been well reviewed by 
Studnicka (’98) and O. Schultze (07). F. E. Schulze (’67) 
speaks of ‘durchsetzender Poren.’ In his later works (’69, ’88, 
and ’96), however, he changes his interpretation and regards the 
margin as having a ‘lamellésvacuolizierten’ or ‘gitternetzartigen’ 
structure. He figures (’69, Taf. 18, Fig. 21-24) oval and round 
bodies contained in the vacuoles, suggesting a connection with 
some secretory activity of the upper layer of cells. 
Leydig (’79), in his work on Pleurodeles waltlii, interprets 
the striations as due to thread-like protoplasmic structures lying 
in ‘Rohrchen’ of the cuticula. Wolff (89, Triton and Sala- 
mandra atra) distinguishes two parts in the outer edge of the 
cells; one, a clear outer homogeneous layer, the ‘cuticula,’ and 
the other, a wider striated zone, the ‘pseudocuticula.’ 
Cohn (’95, axolotl) identifies the striations as fine protoplasmic 
threads with the interfilar spaces filled with some dense, more 
resistant substance. In many cases, according to his description, 
no definite striations are present and the margin appears as an 
irregularly arranged protoplasmic network. | 
Studni¢ka, in 1898, when discussing the appearance of the 
cuticula in surface view, says that it ‘‘aus ihre ganze Dicke 
durchsetzenden Lamellen gebaut ist, die so miteinander verbun- 
den sind, dass sie die Wande langer réhrenférmiger Vacuolen 
vorstellen.”” In salamander larvae Prowazek (’01) finds that the 
cuticular margin resembles quite closely the alveolar margin of 
many Protozoa. Schubotz (’06), while denying the presence of 
any secretory activity, such as suggested by F. E. Schulze, 
claims for the cuticular margin an alveolar structure which is 
but the expression of the alveolar structure of the protoplasm. 
O. Schultze (’06, ’07) upholds the idea of the alveolar nature 
of the cuticular margin and concludes (’07, p. 556) his comparison 
of the condition of the margin in the larvae of the Anura and 
in salamanders with the following statement: ‘Es unterliegt 
aber keinen Zweifel, dass wir es hier, ebenso wie bei Anuren, mit 
einem wabenartigen, aus nebeneinander gereihten réhrenférmigen 
Alveolen aufgebauten Saum zu tun haben.” He finds also that 
_ this layer has somewhat of a secretory function and describes 
