176 Transactions of the Society. 



panicles of pistillate flowers of Brayera antlulmintica Kunth 

 (N.O. Eosacese). This drug is frequently adulterated by the 

 admixture of staminate flowers. The pistillate flowers always 

 yield a few pollen grains which have lodged among the floral whorls 

 or are adherent to the stigmas, but beyond this very small number 

 pollen grains should be absent. It has been shown by Arthur 

 Meyer (7) that this number should not exceed 200 per milligramme, 

 ^nd if more than this number are found the presence of staminate 

 flowers in excessive amount is definitely established. 



In the case of Insect Flowers, one desires to find a powder 

 having as high a number as possible of the characteristic pollen 

 grains. Insect powder consists of the powdered unexpanded 

 flower-heads of Chrysanthenunn cincraricefoliuni Vis (N.O. Com- 

 positae), and if admixed with fully expanded flower-heads an 

 inferior article results. The more fully expanded heads contain 

 less pollen grains, and, if present in the powder, considerably lower 

 the number of pollen grains per milligramme. Lehmann and 

 Trottner {IJ/) have show^n that a powder made from the buds of 

 Dalmatian Insect Flowers contains about 2000 pollen grains per 

 milligramme, while partly expanded flowers yield 1000 to 2000 

 pollen grains per milligramme, and they suggest that any powder 

 containing less than 500 per milligramme should be rejected as of 

 inferior quality. The followiDg example shows how this number 

 ■was determined in the case of a sample of insect powder recently 

 submitted to the author for examination as to its quality : — 



Number of Pollen Grains per Milligramme 

 OF Insect Pow^der. 



One grm. of the insect powder was carefully mixed with 

 €'05 grm. of lycopodium, and from the mixture a crude fibre was 

 prepared by boiling it in a porcelain disli for thirty seconds with 

 50 c.c. of 10 p.c. nitric acid, and filtering under reduced pressure 

 through a piece of moistened Horrockses' longcloth M. 2, stretched 

 over a Buchner funnel supported in a filtering flask. The residue 

 on the cloth was washed with about 100 c.c. of boiling water, 

 returned to the dish and boiled for thirty seconds with 50 c.c. of 

 2 '5 p.c. aqueous caustic soda, filtered through the cloth at the 

 pump and washed with boiling water. The crude fibre containing 

 the lycopodium was removed from the strainer and carefully mixed 

 with mucilage of tragacanth until the volume "was about 20 c.c. ; 

 the whole was Avell shaken in a stoppered tube and a drop was 

 mounted for microscopical examination. The number of pollen 

 grains was counted in a strip across a diameter of the cover-glass 

 having a width equal to the diameter of the field of view" in the 

 microscope. This number was found to be 71. The number of 



