Agricultural Research in New Hampshire 65 



a soil pH of 6.0 and to the others lime was applied alternately to raise 

 the pH to 7.0. Two applications were made, one on September 15 and 

 the other on October 14. 



Counts of the production of blooms were taken until February 3. 

 Gathering of data was discontinued at this time because of what appeared 

 to be a toxic condition of the soil. The plants were unhealthy in appear- 

 ance. Since then the plants have become better established, and it is 

 expected that more data will be secured next winter. 



The limited results so far obtained indicate no difference in effects 

 of liming and no lime, but there was considerably greater production of 

 blooms in the warm temperature. 



A group of seedling plants were grown in sand culture with nutrient 

 solutions. Half of them were supplied a solution in which the nitrogen 

 was in the form of nitrate and the others were given ammonium ion as 

 a source of nitrogen. In general, the seedlings had less chlorosis in the 

 ammonium series, but what few blooms there were appeared more numer- 

 ous on the nitrate series. These were transferred to pots of soil on 

 February 28. (Stuart Dunn, W. D. Holley) 



Sensitive Fern Poisoning in Horses 



This project was started to determine if sensitive fern Onoclea sensi- 

 bilis is poisonous to horses. 



Suitable stable room was made on campus, and three horses were 

 purchased, one of which proved unsuited to feed. Hay was purchased 

 and transported from the Connecticut Valley, hay which was known to 

 be contaminated with sensitive fern and from a section where apparent 

 poisoning had been frequently reported. 



A botanical analysis of the hay was made. The average sensitive 

 fern content of the first lot of hay was 24.25 per cent, of the second lot 

 2.7 per cent. A chemical analysis of pure specimens of fern showed no 

 cyanogen content. 



One horse began to show symptoms of a central nervous disturbance 

 after six weeks. The symptoms were progressive from slight incoordina- 

 tion to prostration with partial blindness and paralysis of the alimentary 

 tract. Necropsy revealed icterus, emaciation, paralysis of stomach and 

 an edema of right cerebral hemisphere. A histopathological examination 

 of various tissues revealed only acute Changes of significance in the brain. 

 These were edema, congestion, and degeneration of the neuron cells with 

 an infiltration of glia-cells around the affected neurons. A second brain 

 obtained from a field case revealed the same microscopic lesions distri- 

 buted over both cerebral hemispheres. A second horse developed a 

 hyperesthesia over the entire body after about ten weeks of feeding. This 

 lasted about four weeks and then gradually subsided. Since this was 

 general over the body and no local lesions developed, it is probable that 

 they were the result of lesions of the central nervous system. 



To date, the results have been inconclusive but an attempt will be 

 made to collect and post additional cases from the field for comparison 

 with our results. (F. S. Prince, E. F. Waller, A. R. Hodgdon, L. V. 

 Tirrell, T. G. Phillips) 



