FUNGI 11 



hydroxide or sodium hydroxide, but great care must be exercised, as 

 otherwise the markings are destroyed. 



In making microscopic examinations it is important that the 

 diatoms be uniformly distributed. This can be accomplished by 

 placing a small quantity of the material in a 1- or 2-drachm homeo- 

 pathic vial and nearly filling with water. The mixture is vigorously 

 shaken, a small quantity is removed, transferred to another .vial 

 containing distilled water, and after vigorously shaking the mixture 

 remove about 10 minims and place upon a slide. The excess of 

 water is allowed to evaporate, the slide passed through a flame two 

 or three times and the material mounted in Canada balsam. Of 

 course examinations can be made direct in water. In the identifica- 

 tion of the various genera and species it is necessary to bear in mind 

 that there are two and sometimes even three views which may be 

 obtained of the same diatom. Some of the common forms of diatoms 

 occurring in commercial Siliceous Earth are shown in Fig. 3. 



r FUNGI 



The fungi comprise a multitude of lower plants of quite diverse 

 structure. They are distinguished by the fact that they do not 

 produce chloroplastids and hence are either parasitic or saprophytic. 

 It has been estimated that the several groups comprise about 65,000 

 species. The economic relations of the Fungi are of great impor- 

 tance, causing as they do considerable depredation to both animal and 

 plant life. Some few are edible and are even cultivated for this pur- 

 pose. Others are exceedingly toxic and not infrequently gathered 

 with some of the edible forms. Relatively few are used in medicine, 

 and of these Ergot is official in nearly all of the Pharmacopoeias. 



ERGOTA. Ergot of Rye. The sclerotium of Claviceps purpurea 

 (Fam. Hypocreacese), a fungus having two distinct periods in its life 

 history an active and a resting stage. During the latter it forms a 

 compact mycelium, or sclerotium, which replaces the flowers and 

 grains of rye. Ergot is picked by hand from the ears of rye, or it is 

 separated after the threshing of the rye; it is carefully dried, and pre- 

 served against the attacks of insects by the use of small quantities 

 of carbon-tetrachloride or chloroform. It deteriorates- with age, 

 particularly when powdered, and is not considered so valuable after 

 one year. Various methods have been proposed for preparing the 

 drug so as to preserve its medicinal properties for a longer period of 

 time. Grover proposed the removal of the oil and Moss found the 

 drug thus treated to retain its therapeutic value for six and a half 



