361 



in den wesentlichsten Puncten wenigstens übereinstimmt, und daß 

 die bezüglichen Verhältnisse eine falsche Deutung erfahren haben« 

 {p. 571). 



A renewed study of Temnocephala with the advantage of better 

 and more varied material, prepared, in the case of some of the species, 

 by a variety of different methods, and, above all, with a more critical 

 examination of details, has led to a good many additions to what I 

 had previously observed with regard to the histology and some recti- 

 fications of errors. But there has never been the slightest doubt 

 thrown by those new observations on the general correctness of my 

 former account of the minute structure of the integument ; on the con- 

 trary, this has been confirmed and reconfirmed with each new method 

 employed and each new species studied. So that I am sorry to say 

 that I must turn round to Dr. Brandes and suggest to him, in the 

 most friendly manner possible, that perhaps a comparison with spe- 

 cimens of other species, such as I hope shortly to enable him to carry 

 out, will lead him to make different deductions from what he has him- 

 self observed in the case of Temnocephala brevicornis . This is not the 

 place for details, but the following points are readily demonstrable 

 with regard to the integument of the Australian species of Temno- 

 cephala : it consists of three distinct layers — a cuticle, an epidermis 

 or nucleated protoplasmic layer, and a homogeneous non-protoplasmic 

 layer, which, for lack of a better name, I have called basement mem- 

 brane. All these are pierced by ducts (pore-canals) of the integumen- 

 tary glands. My figure (Quart. Journ, Microsc. Sci. Vol. XXVIII. 

 pi. XXI fig. 1) is not »außerordentlich schematisch« as Dr. Brandes 

 supposes : it represents very fairly a «transverse section through the 

 body- wall of Temnocephala fasciataci, as stated in the explanation of 

 the plates; some of the details require modification, but in essentials 

 it reproduces what is to be seen in any good series of sections. If 

 Dr. Brandes had used this figure to interpret his sections instead of 

 working in the reverse way he would perhaps have arrived at more 

 sound conclusions. But of this, of course, I am uncertain: it may be 

 that Temnocephala brevicornis is different, as regards this part of its 

 structure, from its Australian and New Zealand allies. It surely must 

 be so as regards the longitudinal layer of muscular fibres, which Dr. 

 Brandes says I have «thorougly wrongly figured and described«. 

 »Auch hier treten die contractilen Röhren zu einem auf Querschnitten 

 netzartig erscheinenden Gewebe zusammen, das sich ganz allmählich 

 in das parenchymatische Bindegewebe fortsetzt.« When I read such a 

 Statement as this I can only conclude either that Temnocephala brevi- 

 cornis is very different indeed from the other members of the group, 



