Zöology; a textbook for colleges and universities . A Drawing by R. Weber FIG. 41. Types of Protozoa. A, Shell of Lagena (Foraminifera) Marine; B, Stylo-cephalus, a gregarine parasitic in beetles; C, Quadrulella, a freshwater much magnified. PROTOZOA 193 division, but the individuals may frequently be seen toconjugate, whereby a certain amount of their proto-plasmic substance is interchanged. This differs from y-iW/ Wfl T^«.7S-^S^T? /^>%fe> n. ^^^ Drawing by W. P. Hay FIG. 42. Paramecium. .4, anterior; B, posterior end; m, oral opening; cv1, an-terior contractile vacuole in
Zöology; a textbook for colleges and universities . A Drawing by R. Weber FIG. 41. Types of Protozoa. A, Shell of Lagena (Foraminifera) Marine; B, Stylo-cephalus, a gregarine parasitic in beetles; C, Quadrulella, a freshwater much magnified. PROTOZOA 193 division, but the individuals may frequently be seen toconjugate, whereby a certain amount of their proto-plasmic substance is interchanged. This differs from y-iW/ Wfl T^«.7S-^S^T? /^>%fe> n. ^^^ Drawing by W. P. Hay FIG. 42. Paramecium. .4, anterior; B, posterior end; m, oral opening; cv1, an-terior contractile vacuole in contraction; cv2, posterior contractile vacuole in stateof expansion; /, food masses; w1, micronucleus; w2, macronucleus. Greatly mag-nified. the sexual reproduction of the Sporozoa, and it canhardly be said that sex exists, since the conjugatingindividuals are alike. In the Suctoria cilia are nearlyalways absent in the adult, which possesses tentaclesinstead. Cilia are by no means confined to the Protozoa ; thusthey exist in the human windpipe, where they serve toremove the accumulations of mucus and dust. CHAPTER TWENTY-FIVE PROTOZOA AND HEREDITY Races of I- THE species of fresh-water Protozoa, widely dis- Protozoa tributed over the earth, are remarkably constant inwhat we call their specific characters. When minutelystudied, however, they are found to vary within , and it appears that there exist numerousminor races, too much alike to
Size: 2433px × 1027px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectzoology, bookyear1920
