It may also be mentioned here that _Babesia_ (_Piroplasma_) _canis_ has been successfully cultivated _in vitro_ by Bass’s method. This has been accomplished by Thomson and Fantham,[209] Ziemann, and Toyoda in 1913. J. G. Thomson and Fantham used the simplified Bass technique recorded above, namely, infected blood and glucose, incubating at 37° C. In one of the _B. canis_ cultures, starting with heart blood of a dog containing corpuscles infected with one, two, or, exceptionally, four piroplasmata, Thomson and Fantham succeeded in obtaining a maximum of thirty-two merozoites in a corpuscle. The cultures are infective to dogs and sub-cultures have been obtained. [209] _Annals Trop. Med. and Parasitol._, vii, p. 621. Family. *Piroplasmidæ*, França. The parasites included in this provisional family or group belong to the Hæmosporidia. They are minute organisms, sometimes amœboid, but usually possessing a definite form. They are endoglobular, being contained within mammalian red blood corpuscles, but they produce no pigment. The true Piroplasmata, belonging to the genus _Babesia_, destroy the host corpuscles, setting free the hæmoglobin, which is excreted by the kidneys of the cow, sheep, horse, dog, etc., acting as host. The disease produced, variously called piroplasmosis or babesiasis, is consequently characterized by a red coloration of the urine known as hæmoglobinuria, or popularly as “red-water.” One of the best known piroplasms is _Piroplasma bigeminum_ or _Babesia bovis_ (probably the latter name is correct), which is the causal agent of “Texas fever” or “red-water” in cattle and is spread by ticks. [Illustration: FIG. 90.--_Nuttallia equi_, life-cycle as seen in red blood corpuscles in stained preparations of peripheral blood. (After Nuttall and Strickland.)] Of recent years, researches on the morphology of these blood parasites has led to their separation into various genera and species. However, our knowledge is still very far from complete. The various genera recognized by França[210] (1909), and placed in a provisional family, Piroplasmidæ, may be listed, though further research may lead to emendations:-- [210] _Arch. Inst. Bact. Camara Pestana_, iii, p. 11. (1) _Babesia_ (Starcovici) or _Piroplasma_ (Patton). Pyriform parasites, dividing by a special form of budding or gemmation with chromatin forking, as well as by direct binary fission. Parasitic in oxen, dogs, sheep, horses, etc. (2) _Theileria_ (Bettencourt, França and Borges). Rod-shaped and oval parasites occurring in cattle and deer. _T. parva_ is the pathogenic agent of African East Coast fever in cattle. (3) _Nuttallia_ (França). Oval or pear-shaped parasites, with multiplication in the form of a cross. _N. equi_[211] (fig. 90) of equine “piroplasmosis” (nuttalliosis). _N. herpestidis_ in a mongoose. [211] _Parasitology_, v (1912), p. 65.