4r!0 



STATE BOARD OF AGRICULTURE. 



TABLE XII.— ACTIVE LARVAE OBSERVED. 



Treatment March 21, 1014. 



1. Liq. carbon bisulphide 



2. Vapor carbon bi' 



sulphide 



3. HgCl2 1-100 



4. CuS04 20% solution... 



5. Lime-sulf. full strength 



6. H2SO4 1-100 



7. H2S04 1-50 



8. H2SO4I-25 



9. H2SO4 full strength... 



10. Formaldehyde 1-100... 



11. Formaldehyde 1-25 



12. Formaldehyde 1-10. .. . 



No. of 

 eggs used. 



3000 



5000 

 4000 

 3000 

 5000 

 3000 

 3000 

 3000 

 3000 

 2000 

 3000 

 3000 



March 22. 



None 



None 

 None 

 None 

 None 

 Abundant 

 Very many 

 None 

 None 

 None 

 None 

 None 



March 23. 



None 



None 

 None 

 None 

 None 



Abundant 



Very many 



None 



None 



Abundant 



One 



None 



March 24. 



None 



None 

 None 



Abundant 

 None 



Used for cu 



Used for cu 



None 



None 



Very many 



Two 



Abundant 



March 25. 



One 



None 



Two 



Abundant 



None 



Ituring experi 



Ituring experi 



None 



None 



Very many 



Abundant 



Abundant 



March 26. 



One 



None 



Many 



Many 



Abundant 



mcnt. 



ment. 



Abundant 



None 



Very many 



Very many 



Many 



March 27. 



Abundant 



None 

 Many 

 Many 

 Many 



Abundaut 



None 



Very many 



Very many 



Many 



With the exception of the carbon bisulphide vapor treatment for six 

 and one-quarter hours, and the full strength sulphuric arid treatment, 

 it will be observed that the results of the various treatments of this ex- 

 periment correspond with those of the previous experiments, where tubes 

 of agar were used. As there was no more inhibition of hatching in 

 this last experiment, where plain agar was used, than in the other tests, 

 where synthetic agar was employed, it would seem that the various salts 

 of the synthetic agar did not reduce the inhibitory powers of the chemi- 

 cals used in the treatments. 



EXPERIMENT XIII. 



It was thought advisable to repeat the carbon bisulphide treatments 

 to get more definite data than the previous experiments had supplied. 

 March 23, 1914, dissected a number of egg masses from knots on lettuce 

 roots, and divided them into three lots. After treatment, each lot was 

 transferred to a tube of synthetic agar while still wet. 



1. Placed the first lot in pure liquid carbon bisulphide for a few min- 



utes. 



2. Placed the second lot in carbon bisulphide vapor for one hour. 



3. Exposed the third lot to strong carbon bisulphide vapor for six- 



teen and one-half hours. 



The results of this experiment are given in Table XIII. 



TABLE XIII.— ACTIVE LARVAE OBSERVED. 



In the case of the liquid treatment and the vapor treatment for one 

 hour, it will be observed that abundant larvie subsequently hatched from 

 the eggs, while none hatched from the eggs exposed to the carbon bi- 

 sulphide vapor for sixteen and one-half hours. From this it would ap- 



