180 KANSAS UNIVERSITY SCIENCE BULLETIN. 



sectioned and mounted on slides. In the latter case, each 

 slide bears in the upper right-hand corner the accession 

 number of the embryo and the number of the slide in the se- 

 ries. (Thus the fifth slide of embryo No. 70 would be marked 

 y.) This marking is done permanently with a diamond 

 point ; this obviates the annoyance incident to the loss of 

 paper labels ; these can, however, be used in addition to the 

 numbers, with advantage in some cases. A record of each 

 embryo and slide is kept by a card catalogue system. For 

 this purpose a set of cards has been devised by Mr. R. E. 

 Scammon, of this department. He, however, expects to de- 

 scribe these in a separate paper. 



For class use, any series can be divided up into sets as de- 

 sired, as brain sets, heart sets, etc. For containers of these 

 sets, the flat, pressed-board boxes manufactured by Theodore 

 Schroter, of Leipzig, are very convenient. They can be ob- 

 tained of various sizes as desired, and have the advantages of 

 compactness and lightness. For storing series of more than 

 six slides, ordinary slide boxes of 100 capacity are used. 

 Standard sets are filed away in the flat containers, but inci- 

 dental sets are better reassembled in their regular containers 

 when not in use. This system of handling them makes any 

 slide of a collection of any size available for instant refer- 

 ence. It also reduces to a minimum the work of keeping the 

 collection in order, since any "stray" slide can be quickly 

 restored to its place at any time. 



