2430 Journal of Applied Microscopy 



to stimulation for 15 minutes and using the light from the mirror of the micro- 

 scope each time. The chlorophyll band, which presents its broad surface to 

 diffuse light, presents only the edge to strong light. 



(b) In plant organs. The leaves of many common plants, particularly those 

 of the Leguminosae, assume positions in bright sunlight different from those 

 taken in diffuse light. Examine the leaves of Baptisia, Lonicera, Oxalis, Cassia, 

 or Phaseolus to determine at what time in the day the paraheliotropic position 

 is assumed, the different leaf positions on the different parts of the plant, the 

 means by which the paraheliotropic position is acquired, and the time of day 

 when the paraheliotropic position is relinquished. Observe how the leaves 

 behave themselves on a cloudy day. 



2. Immediate Effect of Light upon Movement. — Find, out of doors, a dandelion 

 in blossom. Cover the plant with a tiower-crock, or other suitable object which 

 will exclude all light. Observe the action of the flower at intervals of 30 min- 

 ates until fully closed, record the latent period and the temperature. Subse- 

 quently remove the cover and observe the time of opening. 



When one plant is covered with a double-walled bell-jar containing a solution 

 of potassium bichromate, and another with one containing a solution of ammonia- 

 cal copper sulphate, it will be seen that the orange light acts as a dark screen 

 while the blue light acts as daylight. 



3. Nyctitropic Movements. — The alternation of day and night sets up a series 

 of reactions quite similar to those obtained in the preceding experiment and are 

 known as nyctitropic movements. Study, out of doors, the sensitive plant 

 {Mimosa piid/ca), clover {Trifoliiuii repens), oxalis {Oxalis acefosclla), or Cassia nidi- 

 fans to determine the time in the evening when the leaves close or fall and the 

 time in the morning when they unfold. These observations are to be made with 

 reference to sunshine and temperature. 



By covering individual plants observe what effect darkness has on the clos- 

 ing of leaves at night and their opening in the morning. 

 University of Michigan. Howard S. ReeD. 



Willbrand recommends a slight departure from the usual eosin-methylen blue 

 method of staining blood specimens. To the following solution, 50 per cent, 

 solution of eosin in 70 per cent, alcohol, equal quantity of concentrated watery 

 solution of methylen blue for each 50 ccm., add 10 to 15 drops of a one per cent- 

 acetic acid solution. The preparations are placed in this solution and warmed 

 until gas bubbles come off. The erythrocytes are stained red, the nuclei dark 

 blue, the neutrophile granules violet, the acidophiles red (eosinophiles), and the 

 mast cell granules intense blue. The technique is simple, and results are good. 

 Care should be exercised in the heating of the specimens, however, as artefacts 

 are liable to be formed, and may prove mxsXedidxng— Interstate Medical JonrnaL 



