HAY 61 



This will give valuable information as to the time of cutting. A quan- 

 tity of the "dust" is placed in a watch glass, moistened with water and a 

 few drops of caustic potash solution and examined under a coverglass 

 with both a low and a high power lens. Among the foreign matter 

 present there may be hay mites (Acarus foenarius), parasitic fungi, 

 molds, dust, mud and slime. Of the parastic fungi there should be men- 

 tioned ergot (blackish hornlike structures 1 to 2 cm. long), smut (black- 

 ish, sootlike powder), rust (rust-colored or black dustlike heaps or stripes 

 on the leaves or culms), false mildew (whitish to gray-violet, effaceable 

 moldy layers, usually on the under side of the leaves), true mildew 

 (grayish white coating with black puncta), Epichloe (brownish felt sur- 

 rounding the culms of grasses), leaf spot disease (yellow, reddish, brown- 

 ish spots on leaves, sometimes in the form of zones, yellowish or whitish 

 in the middle from drying, often with very minute black points), etc. 

 Special note should be made of the presence of the hairs of procession- 

 ary caterpillars of the oak {Cnethocampa proccssionea), and those of 

 the pine (C. pinivora), the hawthorne spinner (Porthesia chrysorrhocea), 

 etc., which have frequently been known to cause severe inflammation of 

 the mouth of horses, swelling of the head and urticariform eruptions. 



Hygienic requirements for good meadow hay are that it consist chiefly 

 of sweet grasses or herbs cut before bloom, that it contain few if any 

 grasses or herbs that are unpalatable, noxious, or of low nutritive value, 

 that it be properly harvested, have a fresh or bright color, pleasant 

 aroma, and contain no admixtures of dusty, earthy, slimy or fungus 

 particles. 



Fresh hay with high content of aromatic herbs (coumarin and An- 

 tlwxanthum odoratum, etc.), is frequently so intensely aromatic that 

 even horses (especially in close stables) are affected thereby. A sudden 

 change from old to fresh hay has frequently caused febrile gastrointes- 

 tinal catarrhs, colic, icterus, depression, dullness and even coma, dia- 

 phoresis, etc. The causes of these disturbances have not yet been en- 

 tirely explained. Greedy feeding, imperfect mastication and consquent 

 imperfect insalivation, followed by disturbed digestion, increased bac- 

 terial activity, the formation of toxins and irritating products are no 

 doubt in part responsible. Possibly the morbid processes that are active 

 in these conditions could be looked upon as a form of hay fever. For- 

 merly they were looked upon as the result of coumarin poisoning, a view 

 that has been refuted by Froehner, New hay is still relatively rich in 

 water. When stored it sweats and becomes heated, that is, the water in 

 the cells of the heavier parts of the plants passes out by diffusion, and 

 as a result bacterial activity is increased and excessive heat is produced. 

 The water gradually evaporates and bacterial activity ceases. This entire 

 process takes place to completion in the course of 4 to 8 weeks. 



If hay has been stored too green or too wet (rain and dew), it may 

 become heated to such a degree that spontaneous combustion occurs. 

 This applies especially to second-crop hay, less to straw, bran, malt, saw- 



