THE 



AMERICAN NATURALIST. 



Vol. xvi. — SEPTEMBER, 1882. — No. 9. 



METHODS OF MICROSCOPICAL RESEARCH IN Til 

 ZOOLOGICAL STATION IN NAPLES. 



TN the preparation of this paper Dr. Mayer has allowed me to 

 A make free use of his excellent article, 1 published about two 

 years ago. I have added the methods of Dr. Giesbrecht, Dr, 

 Andres and some others who have worked in the zoological sta 

 tion. Dr. Mayer has further placed at my disposal such improve 

 ments and alterations as he has been able to make since the pub' 

 lication of his paper. I am also deeply indebted to Dr. May 

 for advice and generous assistance, for which I wish here to give 

 expression to my most sincere thanks and grateful appreciation. 



I am still further indebted to Dr. Eisig, Dr. Lang, Dr. Andres, 

 Dr. Giesbrecht, Professor Weismann and Professor Dohrn, all of 

 whom I have had occasion to consult with reference to matter 

 contained in this paper. 



I. Preservative Fluids. 



Killing, hardening and preserving are three kinds of work, 

 requiring for their accomplishment sometimes only a single pre- 

 servative fluid, but in most cases two, three or even more. As 

 the same fluid often does the work of killing and hardening, and 

 sometimes of preserving too, it is impossible to divide them into 

 three classes corresponding to the kinds of work, except by 

 repeating many of them twice, and some of them three times. 

 While it is therefore more convenient to include them all under 

 "preservative fluids," as Dr. Mayer has done, it is none the less 



1 Mayer. « Mittheilungen aus der Zoologischen Station zu Neapel." Vol. II, p. 

 ' l88o> A summary of this paper by Geo. Brook was published in the Natu- 

 r aust, June-Oct., 1SS1. 



