LEGUMINOUS CROPS. 19 



that eel-worms being in the stalks of clover made into hay 

 are taken also into the fields in the nose-bags of cart-horses, 

 and in the fodder supplied to folded sheep, as well as in 

 the manure from animals fed in yards with this hay " 

 (Whitehead).i 



Prevention. — (1) Rotation of Crops. Lawes and Gilbert 

 in their paper on " clover sickness " {Journ. Roy. Agric. 

 Soc, vol. xxi.) state, " that as far as our present knowledge 

 goes, the only means of insuring a good crop of red clover 

 is to allow some years to elapse before repeating the crop 

 upon the same land " ; and Mr. Whitehead states that 

 " oats should also be avoided for some time, especially 

 where deep ploughing cannot be resorted to." (2) Farm- 

 yard manure from horses, etc., fed upon clover and oats 

 infested with these nematoids is " a very common means 

 of spreading infestation." The manure derived from these 

 crops should not be used for leguminous and cereal crops; 

 but may be used for root crops. (3) The clover nematoids 

 also infest the common daisy, crowfoot, shepherd's purse, 

 and similar weeds. These should always be destroyed as 

 far as possible. (4) " The plants upon clover leys where 

 '- clover sickness ' has prevailed, should be buried deeply, 

 in order that they may not be dragged up again to the 

 surface by the harrows catching in their long roots. This, 

 of course, cannot be done upon some light chalk and other 

 soils where the surface mould is shallow, but it should be 

 carried out as far as possible." 



' For further information concerning the life-history, etc., ol 

 various nematoids, see Dr. Bastian's " Monograph " in Transactions 

 Linnean Society, vol. xxv.; Schneider's Monographic der Nematoden, 

 1866 ; Claus' "Ueber einige in Humus lebende Anguillulinen " {Zeit- 

 schriftfur Wissenschaftliche Zoologie, vol. xii.) ; and the paper by Dr. 

 Eitzema Bos in the Biologisehes Centralblatt, vol. vii., No. 9. 



