. Fresh-water biology. Freshwater biology. 9i6 FRESH-WATER BIOLOGY These latter larvae are red in color and are known as "blood ; The color is due to haemoglobin in the blood plasma; the capatity of this substance for oxygen gathering seems to enable these blood worms to live in water that is poor in oxygen. In the preceding pages the principal groups of aquatic insects are briefly characterized, and typical forms are figured. Hints are given for the recognition of the nymphs of Plecoptera on page 885, and of the larvae of aquatic Lepidoptera on page 903. In the fol- lowing pag
. Fresh-water biology. Freshwater biology. 9i6 FRESH-WATER BIOLOGY These latter larvae are red in color and are known as "blood ; The color is due to haemoglobin in the blood plasma; the capatity of this substance for oxygen gathering seems to enable these blood worms to live in water that is poor in oxygen. In the preceding pages the principal groups of aquatic insects are briefly characterized, and typical forms are figured. Hints are given for the recognition of the nymphs of Plecoptera on page 885, and of the larvae of aquatic Lepidoptera on page 903. In the fol- lowing pages keys are given for determining the adults of Trichop- tera and Hemiptera, and for both adults and immature stages of the other orders. An understanding of the venation of the wings is essential to the study of adult insects of most orders, and the following figure (Fig. 1386) is given to illustrate the wing venation and explain the terminology Fig. 1386. The venation of the wings of a stonefly, Chloroperla. Tlie designation of veins is given liere for all succeeding wing figures: C, Costa M, Media Sc, Subcosta C«, Cubitus R, Radius A, Anal veins. The radius has a main stem (Ri) and a principal branch (Rs) on the posterior side. Media is often twice forked, and Cubitus once forked; the recognizable branches are numbered from front to rear: three anal veins are likewise Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ward, Henry Baldwin, 1865-1945; Whipple, George Chandler, 1866-1924. joint author. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectfreshwa, bookyear1918
