THE PRODUCT OF A CHAHGED ENVIRONMENT

G. H. Hudson
1893 Science  
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more » ... drawings in black and white suitable for photoengraving should be suppliedby the contributor. Bejected manuscripts will b e returned t o the authors only wherl the requisite amount of postage accompanies the manuscript. Whatever is intended for insertion must be authenticat,ed b y the name and address of the writer; not necessarily for publication, but as a guaranty of good faith. We do not hold ourselves responsible f o r any view or opinions expressed in the communications of our correspondents. Attention is called t o the "Wants" column. I t is invaluable t o those who use it in soliciting illformation or seokiug new positions. The name and address of applicants should be given in full. so that ansmers will go direct t o them. The "Excbanee " column is likewise open. TOWARD the latter part of September or early in October 1891, a number of pitcher plants (Sarracenia purpurea, L ) were sent to me from Wolf Pond, Franklin Co., N. Y., together with other bog plants, for our school Wardian case. This case is 120 cm. long, 51 cm. wide, 45 cm. deep, and stands before an east window where it does not get very much light, save on sunny mornings. We keep in this case many kinds of mosses, ferns, some fungi, and several small animals such as salamanders, toads, wood-frogs, young alligators, and different insect larva. This case also furnishes abundant material for microscopic study, such as rhizopods, infusorians, rotifers, etc. The pitcher plants were carefully set out in the east side of the case, and for several months the pitchers were kept filled with water, and were occasionally fed with flies and hits of meat. Later in the season the plants were neglected; the pitchers were not filled with water, nor was any kind of animal food given them. In the late spring there were two plants living. These plants had hegun to increase the width of the leaf-like margin of their pitchers while the hoods and tubes themselves were suffering a mt~rked change. These changes were intensified during the summer, and the result is shown by the reproduction of a photograph taken Nov. 5, 1892. This photograph shows a n old and ~o m e w b a t decajed phyllodium from one of the two plants, and, in contrast wilh it, one of the new phyllodia from each. These new phyllodia are bright green, without a trace of the usual coloring, serving to attract insects, save on the very edge of the aborted and flattened hood, where a faint border about 2 mm. deep may be noticed. Some of these hoods have not opened; the hairs which line others are in an Immature and useless condition. The leaf-like margins of these curiously modified petioles, instead of being from onefourth to one-third the width of the tube as in normal specimens, have becorne from three to four times the width of the now weak and Battened tube. The scale photographed with these phyllodia will show the extent of this modlfication. The scale shows inches on the left and qentirnetres on the right. Of the next older phyllodia the larger hoods have decayed, while the tube and its wing-likeexpans~on are still in a healthy condition. This pircher plant grows wlld in Plattsburgh, and I have seen it in many places in the Adirondack region, but I have never noticed such wide margins in a state of nature. Was the change in our Wardian case made because of the absence of animal food, which made it necessary for the plant to look in other directions for its support ? Was i t made because of the absence of the influcrlce of water in its tubes while it was forming these new phyllodia? Was the plant obliged to sacrifice its pitchers in order to extend its chlorophyl-bearing surface on account of the loss of light? The changes made, i t will he noticed, were just those changes which would best bring it into harmony with its changed environment. Was this change made in response to the demands of the new environment, or were the changes but the reversion to a n ancient type consequent simply on the diminished vitality of the plant? This curious change suggests many experiments which might easily be made to determine the extent to which certain lower organisms could vary in response to external fitinxuli, and thus be able to adapt themselves-to unusual conditions in a changed or changing environment. Early in the winter one of the little toads used to get into a large prostrate phyllodium, apparently to take a Fat h We have noticed him a number of times sitting just ~r l t h i n the hood with his body partly in the water. Thered, spotted salamanders crawl over th alligator and share the sunny portions of the case with him Believing these bright-colored beings not fit for food, he has offered the little thingsno violence. One of the small garden toadsdid not fare so well but became a victim of a pair of jaws that broke his bones in their embrace. LETTERS TO THE EDITOR.
doi:10.1126/science.ns-21.535.244 pmid:17836405 fatcat:7qpiohpqbbg45ndkeuoyqudmuy