THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL. 



Vol. XI. M.^Y, 1890. No. 5. 



All communications for this Journal, whether relating to business or to editorial 

 inaffcrs, and all books, pa7)iplilcts, exchanges, etc., should be addressed to Aineji- 

 can Monthly Microscopical Journal, Box 6jo, Washington, D. C. 



European subscriptions may be sent directly to the above address accompanied 

 l)y International Postal Order for Sr.ij per annum, or they may be sent to Messrs. 

 Triibner &^ Co., j/ Ludgate Hill, London, or to Mr. IV. P. Collins, 757 Great 

 Portland street, London, accompanied by the yearly price of five shillings. 



A Microscopic Study of the Cotton Plant. 



By p. H. MELL, 



AUBURN, ALA. 



L Species and Varieties. — There are several species of the cotton 

 known to botanists, but only three are of special commercial import- 

 ance. These three are called : 



Gossypium Bahma., or Egyptian cotton. 



GossypiujH barbadense^ or G. nigrum^ or Sea Lsland cotton, or 

 long staple or black-seed cotton. 



Gossypium herbaceuni^ or G. album., or short staple, or upland or 

 green-seed cotton. 



Monsieur Rohn also divides the species into — 



1. Those with seeds rough and black. . 



2. Those with seeds brownish black and veined. 



3. Those with seeds sprinkled with short hairs. 



4. Those with seeds completely covered with close down. 



The three species above mentioned have been multiplied into twcnt}- 

 or thirty so-called varieties. 



n. What is Cotton Fibre.? — When cotton is first taken from the 

 boll it consists of seed with the germ surrounded by its food, a coating 

 or covering called by oil manufacturers the " hull," and by botanists, 

 outer and inner seed-coats, and the outside envelope of elongated threads 

 or tubes that are attached to the outer seed-coat. These threads are, in 

 fact, simply elongated cells of this coat. These cells cover thickly the 

 whole surface of the seed, and in ginning it is necessary to tear them 

 ort' by rupture at the portion near the seed-coat. Seeds are cleanly 



EXPLANATION OF PLATE. 



Fig. 1. — Common variety of cotton — unfertilized. Fir. 4. — Peerless. 



Fi(.. 2. — Same— blighted. Fig. 5. — Truitt (strong, well-twisted, m.iny- 



FiG. 3. — Cross-sections of (i) Common variety, seeded). 



(2) Rameses, (3) Cherry's cluster, 



(4) Forked-leaf or Okra, (sj Peerless. 



Copyright, 1890, by C. W. Smiley. 



