parts, the microscopist should be thoroughly familiar with the 

 weed seeds which always occur to a greater or less extent in cereal 

 products. While the greater part of them are without harmful 

 effects, two or three more commonly occurring seeds are injurious 

 to cattle and poultry. Halsted^^^ and likewise the United 

 States Department of Agriculture ^2) have put out a collection 

 of the more commonly occurring seeds which will be found of in- 

 estimable assistance to the microscopist. 



In this bulletin it has been our object to cover the ground 

 in as brief a manner as possible and yet give the essential ele- 

 ments of a substance, so as to render its diagnosis certain. It 

 cannot be taken as a complete treatise on the subject, but it 

 is hoped that the more important products have been covered. 

 Free use has been made of all the literature available and credit 

 given to the proper authorities. 



No directions have been given for methods of mounting or clear- 

 ing sections and fragments of tissue, but these can easily be 

 found in Winton^s) or other books on technique. A set of sieves 

 of different sizes will be found convenient to separate the feed 

 into portions of different sized particles. A good hand lens and 

 compound microscope will also be necessary, but as the mount- 

 ing is only temporary, no extensive apparatus is required. 



ACKNOWLEDGMENTS. 



The author at this time wishes to express his appreciation of 

 the kindness of Dr. E. A. Bessey, of the Michigan Agricultural 

 Experiment Station for the loan of parts of Figs. 22, 23, 24, 25, 

 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, and 40; also to 

 Messrs. Wiley and Sons for loan of Fig. 9. Many other fig- 

 ures have been adapted, partially at least, from Winton's "Mi- 

 croscopy of Vegetable Foods". The author wishes to thank Drs. 

 Stone and Lindsey and Mr. Smith, of this Station, for valuable 

 suggestions and material often donated; also Mr. R. E. Torrey 

 for many of the drawings. 



1 One Hundred Species of American Weed Seeds. Issued by B. D. Halsted New Bruns- 

 wick, N. J. 



2 Distribution of Economic Seeds, U. S. Dept. Agr., Prepared in Seed Laboratory by 

 F. C. Coville and G. H. Hicks. Issued 1898. 



3 Microscopy of Vegetable Foods, (Wiley & Sons). 



