204 



TIIK AMERUWX MONTHLY 



[July, 



preparations :iri> to !>«' inadr in this way and placed, blood-side 

 up on the filt»T paptr hrfore you and allowed to dry. If tlio 

 MoiMJ is to l)«' taken iVoni a nianiinal, a small incision is made 

 in the ear Frt>ni the Howing blood a small droji is cauglit on a 

 cover as above described. 



Amphibian or reptilian blood is obtained from the heart. 

 The blood preparations may be fi.xed l)y ]>lacin<; them in a so- 

 lution, composed of equal parts of absolute alcohol and ether, 

 in wliich they remain for an hour as suggested by Nikiforoft'or 

 a.'J Dr. Khrlioh recommends, by exposing them to a temi)erature 

 of from K>C)° to \\0° C for from one-half hour to one hour. 



In cftnut . iiwii is used a very simi)le apparatus shown in above 

 cut for fixing the blood prejtarations. It consists of a co])i)er 

 plate about 15 inches long, 4 inches wide and i inch thick, 

 resting on a metal support. The copper plate is heated at one 

 end with an alcohol or gas flame. If then, at the end of fifteen 

 minutes the glass rod which has been dipped into the water 

 be pa.'^.'^ed over the plate, beginning at the end away from the 

 flame, a j»Iace is reached where the water begins to boil. This 

 region of the coi»|)er ]»late represented by a dotted line on the 

 diagram is looked upon as having a temperature of 1W° C. The 

 blood preparations are placed on the plate (blood side up) be- 

 tween the flame and this imaginery line, near the linp, and 

 heated for a time differing with the stain used. 



If the Neutro])hile stain is to be u.sed, the cover gla.sses on 

 which the blood has been spread need to be fixed for fifteen to 

 thirty minutes. The j»reparations are then placed, blood side 



