TEACHERS DEPARTMENT. 
289 
The Use of Blue Prints in Laboratory Notes. —Blue 
prints may be made very useful in reducing the amount of time 
spent upon note-taking in the laboratory. The apparatus used in 
experiments may be photographed and then each student in turn 
may make enough prints from a particular negative to supply the 
class. In most cases, this takes much less time than it would to 
draw a diagram of the apparatus used besides being a much 
better representation of the experiment. The blue prints may 
be lettered and labeled in the same way as a drawing. 
The teacher may find it convenient in some cases to illustrate 
his lecture by photographing good figures from text-books and 
making blue prints from these negatives rather than to take time 
to draw the illustrations as he talks. Blue prints may be made 
directly from such objects as mosses or leaves by placing them 
against the sensitive paper in the light. 
If one has a dark room, he can easily make his own blue print 
paper. Mell, in his “ Biological Laboratory Methods ” gives the 
following formula: 
“ Blue Prints : 
No. 1. 
53.2 grammes citrate of iron and ammonia,. 1% ounces. 
236.8 cc. water,... 8 
No. 2. 
35.5 grammes ferricyanid of potassium,.. 1^4 ounces. 
236.8 cc. water,. 8 
Mix the equal parts of No. 1 and No. 2, and float the paper 
on the solution for three minutes. Plain Rives paper should be 
used. Hang up to dry in dark room. (International Annual, 
1902.)" W. J. R. 
REVIEWS. 
The Structure and Development of Mosses and Ferns. By Douglas 
Houghton Campbell. Pp. vi-f-657. $4.50. New York: The Mac¬ 
millan Co. 1905. 
This is a second edition of the author’s book bearing this title, though 
the fact is not indicated on the back of the cover, on the title page, nor by 
a reprint of the preface to the first edition. The genuine regret felt when 
it became known that the first edition was exhausted is surpassed by the 
pleasure with which the second edition is being received. Parts of the 
