608 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [2] 



the preservative agent. They should also be capable of being closed se- 

 curely so as to guard against leakage when packed for shipment, and 

 also to prevent evaporation wlien stored away in the cabinet. Eubber 

 corks are probably the best for small vials in which it is designed to 

 preserve small embryos or small organisms. 



Crowding a large number of small specimens into one vial is wrong, 

 and abundant space should left besides the specimens for accommoda- 

 tion of a sufficient amount of the hardening reagent or the preserva- 

 tive fluid which may be used, otherwise it is not possible in most cases 

 to harden the specimens uniformly and quickly, because there is not 

 enough of the reagent around the specimens. Delicate embryos are 

 often distorted in the process of killing and hardening, so as to be bent 

 and twisted, which makes it difficult to get the axis of their bodies into 

 a single plane, which is very desirable, especially if it is intended to 

 prei)are serial sections with the newer forms of the sledge microtome. 

 In order to avoid such xlistortion as much as possible, if embryos or 

 other small animals are killed and hardened immediately in the vials, 

 it is best to cork the latter and lay them, on their sides so that the ob- 

 jects, especially if slender, do not rest in a mass on the bottom, but on 

 the undermost side of the vials. These precautions should be borne in 

 mind in handling recently hatched fish embryos, the tails of the latter 

 being especially liable to become bent and distorted by the weight of 

 those overlying those on the bottom of the vial if the latter is placed 

 upright while the i^rocess of hardening is in progress; 



Packing and labeling. — It is of the utmost importance that small, deli- 

 cate objects should be carefully packed in the bottles when it is pro- 

 loosed to ship them, so that they may not be shaken about, especially 

 if moderately large ; unless this is done important portions may be 

 broken off and lost after the specimens have been hardened by the 

 preservative. To avoid this, the specimen, if large, should be wrapped 

 in pieces of cheese cloth, which may be secured around the object with 

 string. If the objects are small wrapping them carefully in soft tissue 

 paper will be found expedient, or if the bottle should not be full, soft 

 tissue paper crushed into springy masses may be used to fill up the 

 vacant space in the bottles, care being taken that the packing of paper 

 is not forced in too tightly so as to injure the specimens. Paper is bet- 

 ter for this purpose than cotton wool, which, in the case of specimens 

 which have hooked teeth or processes projecting from the body fre- 

 quently becomes entangled with such processes as to cause them to be 

 torn ott" when the specimens are unpacked. Finally, it is a good rule in 

 packing to fill the vials full of the preservative fluid, which keeps the 

 specimens immersed and also prevents injurious shaking when shipped. 



Not less important than the packing is the proper labeling of the 

 specimens. Every vial, if containing only a single specimen or a single 

 series, should be labeled with the date of collection, the locality, and 

 the name of the collector. If a number are seut in the same vessel, each 



