26 CLOVER. 



worms, galls on the roots, &c. — were sent or referred to, but there was 

 no reason for supposing any of these to be doing harm. 



It would save a deal of trouble, and likewise delay in applying 

 proper remedies, if two points regarding signs of Eelworm Stem- 

 sickness were more thoroughly known. 



One is that if the minute white worms or worm-like creatures so 

 often seen about the roots are perceptible to the naked eye, this very 

 circumstance shows that they are not Stem Eelworms. These are 

 only one-twenty-fifth of an inch (or about half a line) in length, and 

 if any reader will take the trouble of trying to mark this amount of an 

 inch on a foot rule, he will be at once convinced how impossible it is 

 to notice a presence of worms of only the above length, and of only a 

 thirtieth part of the breadth, without magnifying powers. 



The other point is that the Stem Eelworm attack is the only one of 

 all those noticed in the preceding pages which is characterized by a 

 definitely deformed kind of growth of shoots and buds, and observation 

 of this very peculiar nature of growth whilst still it was living and 

 open to the application of means of prevention and remedy would 

 probably save much loss. 



Prevention and Remedies. — Observations on the nature and treat- 

 ment of Eelworm infestation will be found entered on in my Annual 

 Reports mentioned below.* 



In the Tenth Report, besides considerations regarding the infestation 

 itself, valuable directions by Dr. Julius Kuhn as to eradicating the 

 pest by special cultivation of the ground and avoiding of infested 

 manure will be found. 



In the Eleventh Report notes are given of this T. devastotrix as in- 

 festing Carnations, Clover, Oats, Rye, and Wheat, but not found to 

 infest Barley; and at p. 70 various common grasses, weeds, &c., are 

 named which have been found liable to infestation. 



In the Twelfth Report are special notes of successful use of sulphate 

 of potash and other dressings. 



In the Thirteenth Report I give, by permission of Dr. J. Ritzema 

 Bos, to whom I have been constantly greatly indebted in the course of 

 my observations for identification of species and other valuable assis- 

 tance, a full-page plate, f with figure of the male and also the female 

 of T. devastatrix magnified 200 times, and of the anterior portion of 

 one of these wormlets magnified 440 times, with magnified figures of 

 eggs, &c., and explanation of plate accompanying. Details are also 



* See Tenth to Fourteenth Annual ReiJorts of Observations of Injurious 

 Insects, also Eighteenth, Twentieth, and Twenty-first Annual Eeports. 



t See Plates I. and II. in 'L'Anguillule de la Tige (Tylenchus devastatrix, 

 Kuhn),' par Dr. J. Ritzema Bos, Prof, a I'Institnt Agricole de I'Etat a Wageningen 

 (now Director at the Laboratory of Phyto-pathology at Amsterdam). 



