INSECT-CATCHING PLANTS. 



409 



under each, the remaining pair being placed near them without 

 any covering. 



The treatment then pursued was directed to ascertain 

 the relative effects of artificial and insect stimulants and 

 "total abstinence." Two of the plants under the cages were 

 supplied only with clear water ; the other two in the next cage 

 received a weekly supply of much-diluted liquid manure from an 

 ordinary stable-tank. The uncovered pair were supplied with 

 clear water like the first, but they were left to exercise their 

 insect-trapping propensities unchecked in any way ; and 

 as the house occupied a low, rather damp situation, they 

 were fully engaged during a good portion of the season, 

 for flying insects of various kinds were that year unusually 

 abundant. 



The plants were carefully watched, and the progress noted 

 with much interest for a considerable time, and, without giving 

 the minute details, the results can be summarised as follows : 

 All the plants grew well, and there was little difference in the 

 size of the leaves or the general strength. Those supplied with 

 diluted liquid manure were perhaps a shade darker in colour than 

 any of the others ; but on the uncovered plants three leaves 

 which had been very actively engaged in the fly-catching 

 business began late in the season to assume a yellowish tint, and 

 ultimately decayed, two on one plant and one on the other. As 

 far as the vegetative organs were concerned this was all the 

 difference observed, but when the flower-spikes appeared the 

 case was altered. Only one of the "unfed" plants produced, 

 flowers, and these were at once seen to be weaker in all points 

 than any of the others ; the liquid-fed and the insect-fed plants 

 had flowers exactly alike in size and strength, but one of the 

 last named produced an imperfect spike, which did not develop 

 freely. Eeadily perceptible differences were noted as the 

 capsules swelled ; those on the total-abstinent plant were the 

 smallest, and those on the other two were full-sized, well- 

 developed fruits. When the seed was gathered the difference 

 was still more marked in favour of the nitrogen-consuming 

 plants of the second and third series. Taking the same number 

 of seeds of each, the weight was found to be in the proportion of 

 nearly one to two ; those from the two series of "fed" plants 

 giving almost double the weight of the other, and they had 



