NARRATIVE OF THE CRUISE. 



441 





" Finally the exceedingly delicate soft parts were successfully examined, both with 

 respect to their most minute characters as well as with reference to tlioir relation to 

 the skeletal structures. In addition to the 

 usual methods of teasing and cutting into 

 sections, it has been found advantageous 

 to stain the specimen with some colouring 

 matter, especially with picrocarmine, alum- 

 carmine, and hsematoxylin. For this pur- 

 pose portions, about the size of peas or beans, 

 were stained whole, then thoroughly washed 

 out with alcohol of gradually increasing- 

 strength, and finally dehydrated with tur- 

 pentine or xylol, embedded in paraffin and 

 cut into sections of varying thickness with 

 the microtome. 



" In some cases it was desirable to obtain 

 in the section not only the delicate soft- 

 tissues but also the hard and brittle flinty 

 skeleton as a complete network ; but the 

 well-known curling up of the thin sections 

 was a serious , hindrance, inasmuch as 

 although the delicate, yet elastic, soft tissues 

 were easily retained in connection, the 

 brittle siliceous web was always obtained 

 in fragments. I sought to discover a means 

 by which this detrimental curling of the 

 sections might be prevented, and after many 

 attempts constructed that small accessory 

 to the microtome which I have described 

 and figured under the name of ' Schnitt- 

 strecker'; 1 by means of this simple instru- 

 ment it was possible to obtain sections, not 

 only of very firm and compact pieces, but 

 also of more delicate and brittle objects, 

 such as the tubes of the genus Farrea, in 

 which not only the soft parts but also the 

 brittle siliceous trabeculse were retained in 

 their normal positions. The sections prepared in this manner proved of assistance in 



1 Zool. Anzeiger., Jahiy. vi, p. 108, 1883. 

 (narb. ohall. exp. — vol. i. — 1884.) 56 



Fig. 163, 



Hyalonema lusittmicutn, Bocage, 

 representative of the Hyalonematida?. 



