194 Lake Maxinkuckee, Physical and Biological Survey 



early stages or after it had fully set. Some taken late in the au- 

 tumn of 1912 were kept all winter in a warm room in a laboratory 

 tank of still water, but made no signs of opening until spring, and 

 then never amounted to a great deal. 



If the buds, before too well set, are placed in a vessel in a warm 

 room they open, they will grow rapidly and fill the vessel with sur- 

 prising quickness. While many of the bladderworts remain a deli- 

 cate translucent green, in many other cases the bladders develop a 

 purple or violet color, and this hue in some cases becomes so deep 

 that the bladders appear jet black or wholly opaque. Such plants, 

 specially where they can be so arranged as to be compared with the 

 green form, have a high ornamental value. A plant kept in a jar 

 developed this rich color. One naturally thinks such bladders are 

 full of insects or prey, but examination often proves them empty 

 or nearly so. 



In the early spring the buds expand and grow with great rapid- 

 ity. Though no plants had been noted before April 15, 1901, on 

 that date plants about two inches long, with bladders of good size, 

 were observed in Lost Lake and Green's marsh and were of a fine 

 purple color. By May 19, one flower seen in Green's marsh ; abund- 

 antly in flower and bud in marsh north of Lost Lake ; May 24 

 many flowers seen, same place. 



Many of the bladders were opened and found empty. A num- 

 ber of bladders were examined in early summer and abundant 

 remains of copepods and some ostracods were found inside the 

 bladders. 



It appears, indeed, to be in the autumn just before the leaves 

 drop off and the bud forms for winter, that these bladders are most 

 active in capturing prey. The structure of the bladder is peculiar, 

 the whole organ bearing considerable supeificial resemblance to a 

 water flea (Daphnia), the long guides projecting from the mouth 

 of the bladder resembling much the anterior legs of the crustacean. 

 The plant probably needs an extra amount of food just before going 

 into hibernation to store up as well as to get material for the musci- 

 laginous secretion, and possibly the entomostraca and hydrachnids, 

 benumbed by the coming winter's cold and seeking a place to hiber- 

 nate, find a place for a long sleep by snuggling up between the guid- 

 ing hairs and under the fatal trap door. Some collected in late 

 autumn in Twin Lakes had the bladders crammed with various 

 organisms, especially with a red hydrachnid that showed brightly 

 through the thin membranes of his trap. Concerning the relation 

 of this plant to fishes, Mr. E. G. Simms, Jr. (Fishing Gazette, May 

 31, 1884, quoted in Bull. U. S. F. C. IV, 1884, 257-8), speaks of it 



