Jan. 17, 1878] 



NATURE 



223 



decide the question only failed through an accident. The 

 present research by Dr. F. Darwin is practically a repeti- 

 tion of the same experiments. 



The widely-spread belief that insectivorous plants 

 thrive equally well when deprived of animal food rests on 

 very insufficient grounds. Many observers have based 

 their opinion on the general appearance of the plants, and 

 in no case has observation been sufficiently extended in 

 point of time or details of comparison. The plan of the 

 present research was therefore (i) To cultivate a large 

 number of plants, (2) To continue observation for a 

 considerable space of time, during which artificial starving 

 and feeding of two sets of plants was to be kept up. (3) 

 To compare the starved and fed plants in a variety of 

 ways and especially as to the production of seed. 



With this object about 2Co plants of Drosera rotundi- 

 folia were transplanted (June 12, 1877), and cultivated 

 in soup-plates filled with moss during the rest of the 

 summer. 



Each plate was' divided into halves by a low wooden 

 partition, one side being destined to be fed with meat, 

 while the plants in the opposite half were to be stir.rved. 

 The plates were placed altogether under a gauze case, so 

 that the " starved " plants might be prevented from ob- 

 taining food by the capture of insects. The method of 

 feeding consisted in supplying each leaf (on the fed sides 

 of the six plates) with one or two small bits of roast meat, 

 each weighing about one-fiftieth of a grain. This opera- 

 tion was repeated every few days from the beginning of 

 July to the first days of September, when the final com- 

 parison of the two sets of plants was made. But long 

 before this it was quite clear that the " fed " plants were 

 profiting by their meat diet. Thus, on July 17 it was 

 evident that the leaves on the "fed" side were of a dis- 

 tinctly brighter green, showing that the increased supply 

 of nitrogen had allowed a more active formation of chlo- 

 rophyll-grains to take place. It may be inferred, partly 

 from microscopical examination of the starch in the 

 leaves, but more certainly from the final comparison of 

 dry weights, that the increase of chlorophyll was accom- 

 panied by an increased formation of cellulose. From this 

 time forward the "fed" sides of the plates were clearly 

 distinguishable by their thriving appearance and their 

 numerous tall and stout flower-stems. 



The advantage gained by the fed plants was estimated 

 in many ways. Thus, on August 7 the ratio between the 

 number of "starved" and "fed" flower stalks was 

 100 : I49'i. And by comparing the number of stems 

 actually in flower it was clear that the starved plants 

 were losing the power of throwing up new flower stems at 

 an earlier date than their rivals. In the middle of August 

 the leaves were counted in three plates, and were found 

 to be 187 on the starved, and 256 on the fed side — or in 

 the ratio of ico : 1369, 



At the beginning of September the seeds being ripe, all 

 the flower-stems were gathered, and the plants of three 

 plates were picked out of the moss and carefully washed. 

 As it seemed probable that one advantage of the fed over 

 the starved plants would be the power of laying by a 

 larger store of reserve-material, three plates were allowed 

 to remain undisturbed after the flower-stems had been 

 gathered. The relative number of plants which will 

 appear in the spiing on the "fed" and "starved" sides 

 will be a means of estimating the relative quantities of 

 reserve-material. 



The following list gives the result of counting, measur- 

 ing, and weighing the various parts of the two sets of 

 plants. It will be seen the number of plants (judging 

 from the three plates examined) were fairly equal on the 

 starved and fed sides of the partitions so that a direct 

 comparison of their produce is allowable : — 

 Ratio between the numlicr of starved and 

 fed plants 100:lor2^ 



' In all cases "starved " = 100. 



Ratio between weights of the plants ex' 



f/««V<r of flower-stems ... loo:l2l'5 



Total number of flower stems ... .., 100 : i64"9 



Sum of the heights of the flower stems ... lOO : r59'9 ' 



Total weight of flower stems 100:231-9 



Total number of capsules 100 : 194 "4 



Average number of seeds per capsule ... 103:1227 



Average weight per seed 100:157*3 



Total calculated number of seeds pro- 

 duced lOO: 241*5 



Total calculated weight of seeds produced 100 : 379*7 



The most important feature in the general result is that 

 the advantage gained by the fed plants is far more con- 

 spicuously shown in all that relates to the seeds and 

 flower-stems than in any other part. Thus the ratio 

 between the weights of the plants, exclusive of flower- 

 stems were as 100 to 121*5 ; while the weights of the 

 flower-stems, including seeds and capsules, were as 100 to 

 231*9. The highest ratio is seen to be between the total 

 weights of seed produced, namely 100 : 379 7 ; and this 

 is intelligible, because a store of nitrogen is laid by in the 

 albuminous seeds. 



Another point is that the difference between the starved 

 and fed plants is more clearly shown in the comparison 

 of weights than of numbers or heights. It is clear that 

 increase of weight is a better proof of increased assimi- 

 lation than any other character. 



It may fairly be said that the above experiments prove 

 beyond a doubt that insectivorous plants are largely 

 benefited by a supply of animal food, and it can no 

 longer be doubted that a similar benefit^ is gained in a 

 state of nature by the capture of insects. 



ALBERT VON HALLER 



ON December 12 last the republic and city of Berne 

 celebrated the centenary of the death of one who is 

 universally recognised as their greatest citizen. The im- 

 portant part played in science by Albert von Haller last 

 century is a sufficient excuse for us, profiting by the 

 occasion of the recent celebration, to enable our readers 

 to appreciate the marvellous aptitude of this eminent man 

 for every kind of work, theoretical and practical ; he was 

 at once a statesman, theologian, and poet, as well as a 

 physiologist, anatomist, and botanist. 



Albert Haller was born at Berne in October, 1708, of a 

 family originally of St. Gall, one of whose members 

 fell by the side of Zwingli in 1531. Very weak in body, 

 like Isaac Newton, in his infancy, he exhibited, like him, 

 an extraordinary precocity, and his avidity for books was 

 something indescribable. Having finished his classical 

 studies brilliantly and rapidly, he went to Tiibingen at the 

 age of fifteen years to study medicine, then soon afcer to 

 Leyden to follow the clinic of the illustrious Boerhaave, 

 on whose works he at a later time pubUshtd a com- 

 mentary which greatly contributed to his renown. Albinus 

 taught him anatomy and J. Gessner botany. At eighteen 

 and a half years he obtained the degree of doctor, and 

 afterwards attended, in London, the teaching of Dr. 

 Winslow. After a sojourn at Paris he returned to Switzer- 

 land and studied mathematics with Jean Bernoulli, and 

 that with such ardour that his friends were constrained 

 to look after him. 



In 1728 he made, with Gessner, his first great Alpine 

 excursion, which, many times repeated, made him, in an 

 eminent degree, master of the Swiss flora. His most 

 celebrated poem, entitled " Die Alpen," was another 

 result of his mountain journeys, which contributed to 

 diffuse among those far away the magic charm of that 

 magnificent scenery.' 



' Therefore the average height of the fed steins is slightly less (loo : 99 'g) 

 than that of the fed. But since equal number* oi plants are taken, the total 

 yield of flower ktems is the fair criterion. 



=» Prince Radzivil, Commander of the Polish Confederate.s having at a 

 later period become acquainted with the poem, could not thiuk ot anything 

 better to signify to the author his satisfaction, than to send him a commission 

 of Major-General. 



