. Microbes & toxins. Bacteriology; Toxins; Antitoxins. 144 MICKOBES AND TOXINS '£=i=)ieb^ really a Second host. It remains infective for about 24 to 48 hours after the moment of drawing infected blood, then for a period of about 17 days it is non-infective, again becoming infective for a period of about 60 days' duration. The trypano- some undergoes in it an evolution with sexual reproduction. The protoplasm of protozoa appears to possess faculties of adaptation and varia- tion much more exten- sive than that of bac- teria. Biologically speaking it is a long journey for a parasite of the s
. Microbes & toxins. Bacteriology; Toxins; Antitoxins. 144 MICKOBES AND TOXINS '£=i=)ieb^ really a Second host. It remains infective for about 24 to 48 hours after the moment of drawing infected blood, then for a period of about 17 days it is non-infective, again becoming infective for a period of about 60 days' duration. The trypano- some undergoes in it an evolution with sexual reproduction. The protoplasm of protozoa appears to possess faculties of adaptation and varia- tion much more exten- sive than that of bac- teria. Biologically speaking it is a long journey for a parasite of the stomach of the mosquito to reach the blood of man. In the successive phases and habitats there are forms and structures so different that it re- quires strict proofs to convince one that it is really the same species. The Leishmania donovani of Kala-azar (a disease of India and the Mediterranean) is in the intestine of a bug a flagellate form: in man it is an intracellular form deprived of all locomotory organs. The degradation resulting from para- sitism has abolished in many forms the characteristic structures and in many cases permits of only provisional classification. These degradation phenomena are more striking among the protozoa because we know on the other hand their complete cycle. The bacteria, as we have seen, have reached in their apparent simplicity perhaps the final stage of degradation, and. Fig. 56.—Glossina palpalis, the tsetse fly which carries 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 Burnet, Etienne, 1873-1960; Broquet, Charles; Scott, William Macdonald. London, W. Heinemann
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectantitox, bookyear1912
