1911.] 



Knowledge of the Protozoa of the Soil. 



175 



No. 6. — Manured greenhouse soil from Waltham Cross, moist. 

 After 1 hr. 10 m. — No active forms. 



„ 6 „ 10 „ — 1 or 2 Col. cucullus, many Col. steinii and Gonostomum affine, all having 

 protoplasm clear and finely granular in appearance. 



This was a " sick " soil, i.e., it no longer possessed the power of yielding heavy crops. 

 The factor limiting bacterial activity was exerting itself fully. 



No. 7.— Soil as 6. 

 After 1 hr. 35 m. — No active forms. 



„ 3 „ 20 „ — 



„ 7 „ 10 „ — Many active Col. steinii and Gonostomum affine. 

 No. 8. — Soil as in 6 and 7. 

 After 1 hr. 30 m. — No active forms. 



„ 4 „ „ — Several Gonostomum affine, 1 or 2 Col. steinii, and 1 Yoi-ticella micro- 

 stoma, free swimming, cylindrical, aboral ciliary ring. Protoplasm 

 of all organisms clear, no food vacuoles. 

 No. 9. — Manured soil from Barnfield, fairly moist. 

 After 1 hr. 40 m. — 1 or 2 Col. steinii, 1 Bal. elongatus, protoplasm clear. 

 „ 2 „ 30 „ — 5 or 6 Col. steinii, 2 or 3 Bal. elongatus. 



„ 5 „ 20 „ — Many Col. cucullus, Col. steinii, Gonostomum affine, 1 or 2 Bal. elongatus 

 and Enchelys. 



The soil had been stored in the same way as 3 since October, 1910. 

 No. 10. — Manured soil from Barnfield, fresh and moist. 

 After hr. 25 m. — No active forms. 



„ 1 „ 5 „ — „ „ 



„ 2 „ „ — „ 



„ 4 „ 35 „ — 1 Col. cucullus, 2 Bal. elongatus, protoplasm clear and finely granular. 

 No. 11. — Soil same as 9. 

 After hr. 50 m. — No active forms. 



„ 1 „ 30 „ — 1 Col. cucullus, protoplasm clear, nucleus easily seen, without staining, 

 under high power. 



„ 3 „ 20 „ ■ — 2 Col. cucullus, protoplasm clear, one caught showing nucleus well, 

 without staining. 



„ 4 „ 30 „ — 1 Col. cucullus, dark in appearance, having a fair number of food 

 vacuoles. 



4 or 5 Gonostmnum affine, 2 caught showing clear protoplasm and 

 nuclei without staining. 

 No. 12. — Soil same as 10. 

 After 1 hr. 20 m. — No active forms. 



„ 2 „ 15 „ — 2 Col. steinii, protoplasm clear. 



„ 5 „ „ ■ — 1 Col. steinii, 1 or 2 Bal. elongatus, protoplasm clear, 1 Gon. affine, 



nuclei showing well without staining. 

 „ 7 „ „ ■ — Many Col. cucullus, Col. steinii, Bal. elongatus, all having clear proto- 

 plasm, and a few food vacuoles. 

 1 Epistylis coarctata, cylindrical, free swimming, 1 or 2 food vacuoles. 

 No. 13. — Soil, a mixture of toluene-evaporated + 50 per cent, untreated soil, fairly moist. 

 After 1 hr. 10 m. — No active forms. 

 „ 1 „ 55 „ — 1 Bal. elongatus. 

 „ 3 „ 30 „ — No active forms. 



„ 6 „ „ — 1 Col. cucullus, 5 or 6 Col. steinii, protoplasm clear and nuclei showing 

 well. 



