2 S. GOTO. 



tioning. Moreover, corrosive sublimate can be sd easily carried about, 



and its saturated solution so easily made that it is, generally speaking, 



by far the best reagent for use on a collecting tour. The specimens 



were preserved in 70 7o alcohol. 



For staining sections I have almost excljlsively used Kleinen- 



berg's solution of haematoxylin. I have tried picro-carmin and 



borax-carmin, but they did not give good results, although the latter 



was very excellent for staining specimens mounted in toto. I have 



also tried cochineal tincture so highly recommended by Lang for the 



glandular cells of polyclads ; but it gave no differential staining 



whatever. 



For preparation in toto, the specimens were killed under the 

 pressure of a cover-slip over the flame of an alcohol lamp, and were 

 directly immersed in 70 "/o alcohol, in which they were preserved 

 together Avith other specimens. For staining I have used borax- 

 carmin ; the over-stain being thoroughly washed out with acidulated 

 70 °/o alcohol. In most specimens, only the internal organs and the 

 nuclei of the mesenchyma remain stained, while the mesenchyma 

 itself is wholly decolourised, so that the result forms altogether a very 

 beautiful object under the microscope. 



To Prof. Ijima and Prof. Mitsukuri are due my warmest 

 thanks both for supervision and for giving me suggestions and the 

 most friendly assistance. To Profs. Parona and Perugia of 

 Genoa, Prof. Monticelli of Naples, and Prof. Kamsay Wright 

 of Toronto, I am indebted for their courtesy in sending me their 

 papers on ectoparasitic Trematodes. Finally but not least my best 

 thanks are due to the authorities of the Imperial University for 

 taking charge of the publication of the paper. 



