44 



Corn Cockle. 



[APRIL, 



The toxic principle is not removed by the heat of an 

 ordinary oven in baking, or by boiling. 



Though the foregoing notes are somewhat contradictory 

 in character, it is clear that poisoning by corn cockle has 

 commonly occurred under a variety of conditions, and the 

 evidence is sufficiently conclusive to show that the ingestion 

 of the seeds should be carefully avoided, and waste material 

 from thrashing, winnowing, or otherwise cleaning grain 

 should always be destroyed when it contains more than a 

 small amount of cockle seed. Indeed, it appears to be 

 generally the best plan to burn all foul screenings. 



Identification in Food-stuffs. — When ground up with 

 grain, especially wheat, portions of the black, rough seed- 

 coats remain sufficiently large and characteristic to be recog- 

 nised under the microscope. Winton says that "highly 

 characteristic of cockle are the large, more or less elongated 

 (up to 600 /x long) epidermal cells with enormously 

 thickened, deeply sinuous, brown walls. These cells form 

 humps, covered on the outer surface with numerous fine 

 warts." Under these outer cellular warty humps, forming 

 the epidermis, are one or more layers of parenchyma cells, 

 and then follow within the large thin-walled cells composing 

 the endosperm, and containing starch bodies. The starch 

 bodies are spindle-shaped, club-shaped, oval, lance-shaped, 

 or sometimes nearly globular. They are 20 to 100 ^ in 

 diameter, and easily disintegrate in cold water into minute 

 starch grains, stated by Konig to be about 1 /a in diameter, 

 roundish and angled. Cornevin describes the grains as 1 

 to 2 and never over 6 /x in diameter. They are perhaps 

 on the average one-fifteenth the size of the starch grains of 

 wheat. 



The presence of cockle in mill products, therefore, can be 

 diagnosed by the appearance of the epidermal cells, and by 

 the starch grains. 



The chemical tests for corn cockle suggested by Petermann, 



and by Medicus and Kober, are quoted by Konig in the 



volume mentioned below. 



Works of Reference. — Experiment Station Record, U.S. Dept. of 

 Agriculture, Volumes IV., V., XII., XV., XVI. 



Farmers' Bulletin No. 86, U.S. Dept. of Agriculture. 



