421 



vegetable growth useful (is esculents or articles of manufacture. Uuder tliis head 

 may be classed the chemical examination of those new plants or seeds which 

 have proved serviceable to man abroad, and which have been imported or grown 

 for experiment in the gardens of the department. 



2. The examination of certain conditions of agricultural growth which are 

 still matters of doubt or of diii'erence of opinion; e. g., the determination of the 

 most proper time for obtaining sugar from the sorgho plant ; the most economi- 

 cal meth'id of separating its sugars ; the consideration of the value of the beet 

 as a substitute for the cane or other siagar-producing plant ; and the exact re- 

 lation of climate, soil, and period of growth with the amount of sugar in the sap. 



These examinations will generally be carried out upon plants or raw products 

 raised by the department, which Avill thus act as a pioneer in recommending, 

 after rigid investigation, to the agriculturists of the country the cultivation and 

 introduction of new substances, products, and plants. 



3. The examination of cert.ain growing crops of value in all sections, with a 

 view to determine tbe value of various manures at certain periods of growth of 

 the plant. This line of investigation' is now much cultivated in the agricultural 

 laboratories of Europe, but there is ample room for similar researches in the 

 United States. 



4. Tbe examination of any newly discovered minerals, marls, mineral waters, 

 peat beds, or other substances which may be of importance to the agricultural 

 community. Farmers, planters, and othei'S can have such substances examined 

 in the laboratory of the department upon forwarding samples. As the depart- 

 ment was established for the benefit of the whole community, the chemical report 

 of such investigations will be made public through the monthly or yearly reports, 

 whenever it is believed that the information resulting from the examination will 

 be servicea'ole to the interests of agriculture. 



INSECTS INJURIOUS TO COTTON PLANTS -NO, 5, 



HYFERCnmiA VARIA. Packard Pr. Ent. Soc, Phil., vol. 3, p. 384. 



Saturnia io. Harris, 395. 

 Corn Emperor moth, or Io Emperor. 



The foliage of the cotton- 

 plant is also eaten by the cat- 

 erpillar of a large moth. This 

 spiny and stinging caterpillar is 

 often fnuud upon tlie leaf of cot- 

 ton in September ; it feeds like- 

 Avise upon the blades of Indian 

 corn, and. the leaves of the 

 willow, balsam- po})lar, dog- 

 wood, and many other trees. 



