SEVENTEENTH ANNUAL EEPOET. 



381 



''Bureau of Animal Industiy, for Zoological Laboratory." It is 

 always better to forward live specimens when possible, and to send 

 several of each sex if the}^ can be obtained. For transmission they 

 may be placed, without packing, in a pill box or other convenient 

 receptacle. 



Method of examination. — In many cases a tick taken from cattle may 

 be quite positively determined without the aid of a microscope. In 

 view of the importance of avoiding an incorrect determination it is, 

 however, advisable to examine the specimens with a hand lens. No 

 preserving fluid or technique is necessary. The specimen is simply 

 held between the thumb and first finger of the left hand, so that it may 

 easily be turned, and the magnifying glass held in the right hand and 

 brought into focus. 



If finer microscopic work is desired, the specimen may be killed in 

 boiling water or alcohol. The next step depends upon the nature of the 

 stud}^ proposed. If ordinary glycerin preparations of the hard parts are 

 desired the specimen is dissected, the soft parts being cut awa}^ as much 

 as possible. The structure intended for mounting may then be placed 

 in a 2 to 10 per cent solution of caustic potash until the remaining soft 

 tissues are destroyed. Next, transfer the specimen to water, in which 

 it is left (the water being changed once or twice) until the caustic is 

 washed out. Finally, the object is placed on a slide, a drop of glyc- 

 erin added, and the specimen protected with a cover slip; or, if a 

 balsam mount is desired, the specimen is washed as above, after being 

 treated with caustic and then, after being dehydrated by placing it suc- 

 cessively in alcohol of 50, 70, 95, and 100 per cent, transferred to 

 xylene or like fluid and mounted in balsam. Very satisfactory mounts 

 of an entire male, nymph, or larva may be madeb}^ the above methods. 



Section cutting of ticks is difficult and tedious, owing to the thick 

 tegument. A method used by zoologists gives very good sections when 

 one has the patience to carr}^ it out. The entire bod}^ is prepared in 

 the usual wa}^— killed in hot water, sublimate solution, or alcohol — then 

 passed through alcohol (70, 90, and 100 per cent) and xylene, and 

 embedded in paraflin. Before each section is made with the microtome, 

 the exposed surface of the embedded object is covered with a thin film 

 of a colorless solution made from mastixcollodion, absolute alcohol, 

 and ether. The sections are fastened to the slide by a thin film of a 

 solution of equal parts of glycerin and albumen," then treated in the 

 usual way — dissolve paraffin, stain sections, dehydrate, and mount. 



Classification, synonymy., and literature, — Quite recentl}^ Prof . L. G. 

 Neumann has completed a monographic revision of the ticks of the 

 world. For this work he has had not only almost the entire collection of 

 Ixodoidea belonging to this Bureau, but also specimens from numerous 

 ()ther laboratories and collections. ■ 



As the ticks belonging to the Bureau are still in his possession, we 



