24 SU Ill-dim (isi rtiHsa/ //// fJn hJi Inoriii 



'J'lio inoiuliition was (-arried out by means of a fine capillary glass pipette. 

 Later examination and dissection of seedlings revealed the fact that 

 mature and sexually difTerenliated worms were d<'veloped in from 

 24 to 30 days from the date of inoculation. 



Several experiments were also made in which clovers of different 

 kinds were grown on soil heavily infected wnth Ti/lenchu^ dipsaci. It was 

 invariably found that the seedlings of red clover showed a high per- 

 centage ol affected planfs which possessed, at first, swollen hj'pocotyls 

 and later on became stunted and deformed with small wrinkled leaf- 

 blades. 



Kollowini; these early experiments the main experiment which forms 

 the basis of this paper was set up. 



The soil used was that from around the roots of diseased red c^lover 

 from the Universitj' Farm at Cambridge, which had i)een kept for about 

 two months at the bottom of a small galvanised iron bin. All the plants 

 had died down and become withered and brown. 



The soil was crumbled up finely and the tops of the plants were chopjjcd 

 up finely and thoroughly mixed into the soil, with which also a small 

 proportion of silver sand was incorporated. 



This mixture, which it was considered would be highly infective for 

 Tylenchuf! dip.mci, was put in a layer about one inch deep on the top 

 of Hoosfield .soil plus lOper cent, sand in f O-ineh glazed pots, thus forming 

 a shallow layer of infective soil close to the top of the pot. 



Each pot was divided into four quadrants for economy of space by 

 means of glass partitions pressed down into the soil. 



One hundred seeds of each of the following were sown, each in its 

 quadrant, and covered with a thin layer of .sand. 



Red clover — Enghsh, French, Canadian. Wild Knglish. 



C'oiv-grass — English . Swedish . 



Alsikc clover — English, Canadian. 



While clover — Sutton's Mammoth. Wild Cotswold. Wild Kentish, 

 English. Dutch AVhite. 



Kidncif celcli, Sainfoin. Lucerne (Provence), Trejoil. 



All the seeds were sown on the same day, June 1st. The ])ot s were then 

 carefully watered and put out in the wire-covered enclosure and there 

 left for the seedlings to grow under the same conditions of temperature, 

 light, air, moisture, etc. It was hoped by giving throughout all the 

 pots uniform conditions of soil in which the parasites were as equally 

 di.stributed as could be arranged, and by lea\nng them under the same 

 climatic conditions in all cases, that anv differences shown in the inci- 



