[301] C. W. Stiles (“American Medicine,” 1905, ix, p. 682) is of the opinion that Salisbury’s Trichina cystica is identical with Oxyuris vermicularis.
[302] For determining periodicity measured quantities of blood, e.g.., 20 mm.3, should be used. A thick film is made of the whole quantity. The numbers present in this quantity may vary from three or four to 300 or 400.
[303] [Acetic alcohol does well for detecting crescents in thick films of malaria blood.—J. W. W. S.]
[304] Trichinellæ that are unable to penetrate into muscular fibres invariably die, no matter where else they settle; their occurrence in the adipose tissue is disputed, but is still possibly correct, as bundles of muscles are present in the fat of bacon. The Trichinellæ do not settle in heart muscle, although they may reach it in cases of heavy infection; they then die or wander into the pericardium, and eventually into the heart cavities.
[305] It is still a matter of dispute and can hardly be definitely settled whether Trichinellæ were brought to Europe by the sewer rats which invaded Europe at the end of the eighteenth century, or whether they were imported with the Chinese pig in 1820 or 1830, when it was introduced into England and Germany to cross with the native breeds, or whether finally Trichinellæ are also indigenous to Europe.
[306] For instance, extensive epidemics occurred in Hettstädt in 1863 (160 patients, 28 deaths); Hanover, 1864–1865 (more than 300 patients); Hadersleben, 1865 (337 patients, 101 deaths); Potsdam, 1866 (164 patients); Greifswald, 1866 (140 cases, 1 death); Magdeburg, 1866 (240 cases, 16 deaths); Halberstadt, 1867 (100 cases, 20 deaths); Stassfurt, 1869 (over 100 cases); Wernigerode, 1873 (100 cases, 1 death); Chemnitz (194 cases, 3 deaths); Linden, 1874 (400 cases, 140 deaths); Niederzwohren, near Cassel, 1877 (half the population); Diedenhofen, 1877 (99 cases, 10 deaths); Leipzig, 1877 (134 cases, 2 deaths); Ernsleben, 1883 (403 cases, 66 deaths); Strenz-Neuendorf, 1884 (86 cases, 12 deaths), etc. According to Johne, 109 epidemics, with 3,402 cases and 79 deaths, occurred in Saxony between 1860 and 1889. Stiles, in a work recently published, states that there were 8,491 cases of trichinosis with 513 deaths (6·04 per cent.) in Germany from 1860 to 1880; and 6,329 cases and 318 deaths (5·02 per cent.) between 1881–1898. Of these latter, 1881–1898, 3,822 (225 deaths) occurred in Prussia, 1,634 (76 deaths) in Saxony, and 873 (17 deaths) in the remaining states. There is, however, no doubt that many deaths from trichinosis were not recognized, as proved by experience at post-mortems.
[307] Convergent: i.e., the uteri are parallel, converging from the anterior part of body to the vagina, which is near the anus, this position being associated with convergence of the uteri. Divergent: Uteri run anterior and posterior, diverging from the vagina, which in this case is near middle of body.
[308] For nomenclature of rays vide p. 449.
[309] The reports of the city inspection of meat in Berlin state that Strongylidæ in the lungs of pigs are by no means rare; therefore the lungs of 1,941 pigs were condemned between 1885–1886, of 1,641 between 1886–1887, of 3,237 between 1887–1888, of 4,855 between 1888–1889, of 7,197 between 1889–1890, and of 5,574 pigs between 1890–1891, etc. Ostertag found Strongylus apri in 60 per cent. of the pigs examined in the Berlin abattoir; Meyer, in Leipzig, found the parasite in 15 per cent. of the native pigs and in 52 per cent. of the Hungarian pigs.
[310] Dictyocaulus is parasitic in the bronchi.