1 882.] in the Zoological Station in Naples. 701 



borax-carmine, Dr. Eisig's mode of treatment must be pronounced 

 very successful. The process is extremely simple ; a few drops 

 of alcohol are put into a vessel which contains the annelid in its 

 native element, the sea-water ; this is repeated at short intervals 

 until death ensues. After the animal has been thus slowly killed, 

 it may be passed through the different grades of alcohol in the 

 ordinary way, or through other preservative fluids. Objects 

 killed in this manner show no trace of the external crust of pre- 

 cipitates which arises where stronger grades of alcohol are first 

 used. The action of the alcohol is thus moderated, and the ani- 

 mal, dying slowly, remains extended and in such a supple condi- 

 tion that it can easily be placed in any desired position. The 

 violent shock given to animals when thrown alive into alcohol of 

 40 per cent, to 60 per cent., giving rise to wrinkles, folds and dis- 

 tortions of every kind, is thus avoided, together with its bad 

 effects. 



3. Acid Alcohol. — In order to avoid the bad effects of alcohol, 

 such as precipitates, maceration, &c, Dr. Mayer recommends 

 acid alcohol— 



95 volumes 70 per cent, or 90 per cent, alcohol. 

 3 " hydrochloric acid. 1 

 for larger objects, particularly if they are designed for preservation 

 in museums. The fluid should be frequently shaken up, and the 

 object only allowed to remain until thoroughly saturated, then 

 transferred to pure 70 per cent, or 90 per cent, alcohol, which 

 should be changed a few times in order to remove all traces of 

 the acid. For small and tender objects, acid alcohol, although 

 preferable to pure alcohol, gives less satisfactory results than 

 picro-sulphuric acid. 



4. Boiling Alcohol.— -In some cases among the Arthropods, Dr. 

 Mayer has found it difficult to kill immediately by any of the 

 ordinary means, and for such cases recommends boiling absolute 

 alcohol, which kills instantly. For Tracheata this is often the 

 only means by which the dermal tissues can be well preserved, as 

 cold aicohol penetrates too slowly. 



5- Osmic Acid.— Dr. Mayer employs osmic acid as a staining 

 medium for the hairs, bristles, &c, of the dermal skeleton of 

 Arthropods. The luster of Sapphirina is preserved by this acid, 2 



