444 



INSECTIVOROUS PLANTS. 



rill, Republican, 179,976; Young, National, 

 37,687. 



The result of the election of members of 

 the State Legislature was as follows : 



INSECTIVOROUS PLANTS. The fact 

 that certain plants capture insects by aid of a 

 sticky secretion which exudes from their leaves, 

 and inclose them by a shutting action of their 

 leaves, has been long observed by botanists. 

 The best known of these plants was the Dio- 

 naa muscipula, or Venus's fly-trap, in America, 

 and the Drosera or sundew, which grows in 

 peat-bogs in Europe. These species are pro- 

 vided with bristles and tentacles, from the 

 glandular extremities of which the viscid lime 

 which attracts and detains the insects is se- 

 creted. The pitcher-plants entrap the insects 

 which are attracted into their hollow leaves 

 by means of short stiff spines in their mouth, 

 which allow ingress but no egress. The leaves 

 of the bladderwort are provided with sacs 

 which have a similar funnel-shaped mouth 

 guarded by converging needles. Ellis, a con- 

 temporary of Linnaeus, first asserted that the 

 Dioncea was nurtured by the captured insects, 

 since they were suffused by a slimy liquid which 

 dissolved them. Other botanists revived the 

 hypothesis from time to time; but the most 

 extensive investigation of the subject was 

 made by Charles Darwin, who published the 

 results of his observations in a book on insec- 

 tivorous plants in 1876. His observations were 

 supplemented by thosa of Kohn, Hooker, and 

 others. It was established that the structure 

 of various plants is completely adapted to the 

 capture of insects, that the insects are digested 

 by a secretion which possesses the properties 

 of gastric juice, and that they are absorbed by 

 the plant. But there was no proof that the 

 animal substances serve as a true food to the 

 plant, and that the plant is benefited by the 

 diet. Many observers thought that they had 

 found indications to the contrary, and that the 

 operation was abnormal and purely pathologi- 

 cal. This past year Francis Darwin has been 

 engaged in an elaborate series of observations 

 on the habits of the Drosera, which supply the 

 missing link of evidence, and show that that 

 plant is directly and decidedly benefited by its 

 animal food. He planted a number of sundews 

 in pl.ites, placing a wooden partition across 

 the middle of each plate to separate the plants 

 into two divisions. He placed them in a hot- 

 house and covered the whole with fine muslin 

 to prevent the access of insects. He corn- 

 iced his experiment on the 12th of June 



'ing the plants on one side of each plate a 

 regular and frequent supply of animal food in 



the form of pieces of roast beef of about one 

 fiftieth of a grain, while those on the other 

 side of the partition were left entirely to the 

 ordinary sustenance of plants. After the sec- 

 ond day's feeding the experiment was inter- 

 rupted, and first resumed on the 5th of July. 

 By the 15th of July the fed plants were noticed 

 to be much fresher and greener than the others, 

 and a microscopical examination revealed a 

 much larger quantity of chlorophyl than the 

 starved plants, and that the grains of chloro- 

 phyl were loaded with starch ; the nitroge- 

 neous diet therefore promoted the assimilation 

 of plant-food and the storing of reserve mate- 

 rial. By the 5th of August there were found 

 on count to be 49 per cent, more plants in the 

 division fed with beef than in the other, al- 

 though the unfed plants were slightly in excess 

 and more vigorous at the beginning of the ex- 

 periment. By the end of August the plants 

 had blossomed and the seeds were ripe. The 

 seed capsules were cut off and the seeds counted, 

 and the plants in the two divisions were com- 

 pared as to number, size, weight, number of 

 capsules and their weight, and number of seeds 

 and their weight. In one respect only, that of 

 height, the comparison was in favor of the 

 unfed plants, and here only in the proportion 

 of 100 to 99-9. In every other particular they 

 were excelled by the plants which had been 

 supplied with animal food. The portions of 

 the plant connected with the functions of re- 

 production showed the advantage of nitroge- 

 nous food in the most marked degree ; while 

 the proportion between the average weights 

 of the starved and the fed plants was as 100 to 

 141-3 ; the proportion in the number of flower- 

 stalks was 100 to 169*9 ; in the total number 

 of seeds, 100 to 241-5 ; and in the average 

 weight of the seeds, 100 to 379*7. The plants 

 of three plates were left in the hothouse over 

 winter and were again examined in the spring. 

 The rootstocks of the fed plants were consid- 

 erably the largest ; the average weights of the 

 two sorts were as 100 to 213 in favor of the 

 plants which had been fed in the summer. 

 Thus, in spite of the amount of energy and 

 material consumed in the production of two 

 and a half times as many seeds, and four times 

 as great an aggregate weight of seeds, the set 

 of plants nourished with a regular small supply 

 of nitrogenous food during the season (the 

 whole amount taken amounting only to a few 

 grains) were stimulated also to lay up a reserve 

 of food material which enabled them to sub- 

 sist through the winter and come out in the 

 spring more than twice as heavy as the plants 

 which had been deprived of animal nutriment. 

 Similar experiments have been carried on in 

 Germany by Reiss, Kellermann, and Von Rau- 

 mer. The food used by them was aphides 

 instead of meat. Their results were fully in 

 accord with Darwin's. "Whatever be the trans- 

 formation of the organic nitrogenous sub- 

 stances after they have been absorbed into the 

 vegetable structure, these observations estab- 



