TAri->wo];:\is of the sub-family AvrrELLixjN.F. 341 



up the structure of the longitudinal uiuscles very distinctly. 

 I have also employed hasmatein Apathy aud Delafield's 

 ha^matoxylin with good results. lu using the Delatield one 

 can obtain much the same results for the subcuticular cells as 

 with Ehrlich's hsematoxylin if, instead of differentiating 

 with acidulated alcohol and blueing with ammoniated alcohol, 

 one washes the specimens after staining in running water 

 only. The nuclear structures do not stain as cleanly, however, 

 as they do Avhen using the stain in the ordinary way. 



For specimens mounted in toto I use borax carmine; 

 most of my material has been stained with l)ornx carmine 

 before cutting, being re-stained with ha3matoxylin after 

 sectioning. I do not find that this spoils the final result ; on 

 the contrary, one often finds that the borax carmine helps to 

 differentiate the nucleoli from the chromatin bodies in the 

 nuclei. 



My sections are invariably 4/t thick, which appears to be 

 the best thickness for Avitellina material. 



Almost all the drawings have been made with the Leitz oil- 

 immersion YT5- and ocular 2, and are reproduced as far as 

 possible at the same scale. 



I have made sections of Taenia serrata, Goeze; Ano- 

 plocephala magna (Abilgaard) ; Dipylidium caninum, 

 L., and Stilesia hepatica, Wollfhiigel, in order to obtain 

 comparative material fixed, hardened, and stained in the same 

 way. It was unfortunately not possible to obtain Ligula 

 material. 



The Cuticula. Figs. 17-21. 



The cuticula consists of the usual two layers, which seem 

 to have been observed by all recent observers, namely, a thin 

 outer layer (Comidien Schicht, Minckert, 1906) and a 

 thick inner layer (Homogene Schicht, Minckert, 1906), 

 within which lies the extremely thin basal membrane 

 (Grenzstreifen, Minckert). 



The outer layer, or comidial layer, stains very deeply Avith 

 hsematoxylin ; it does not appear to be provided with fine 



