METHOD OF PREPARING AND EXAMINING THICK-FILMS 365 



numbered slides are ranged in consecutive order, numbered side 

 down, upon the box cover. The pricking-needle, well fixed in a 

 large cork, is placed within convenient reach in front of the slide- 

 box. The subject stands to the left of the collector, and the blood 

 is taken from the middle finger of the left hand. The blood films 

 are placed in the box film side down, the numbered ends of the 

 slides all toward the left, and films toward the right. 



In collecting blood specimens, one can save a great deal of time 

 by the use of cards instead of a note-book for recording data. In 

 surveys of schools cards may be distributed among older children 

 and each can be directed to write his name, age, residence or other 

 information. Sometimes these data are more accurately recorded 

 by the child than by the teacher. The child brings his card to 

 the examiner, who takes the blood specimen and enters the slide 

 number on the card. After the results of the microscopic examina- 

 tion has been recorded on the cards, these may be classified by 

 age of child, type of parasite or any other datum. When these 

 results have been tabulated the cards may be arranged alphabeti- 

 cally. 



Any attempt to prevent expense by the use of inferior stains, 

 slides or other necessary apparatus is likely to prove to be poor 

 economy. The time lost in collecting and staining an unserviceable 

 batch of specimens may be worth more than a month's supply of 

 a proper stain. 



