(4) The case reported by Baraban and St. Remy[236] was at once demonstrated as certain. It related to a man who had been executed, and in the laryngeal muscles of whom Sarcosporidia were found; the length of the parasites varied between 150 µ and 1,600 µ, their breadth between 77 µ and 168 µ. The affected muscular fibres were distended to four times their normal thickness. This species was described by Blanchard as “_Miescheria_” _muris_, but according to Vuillemin, it was more probably _Sarcocystis tenella_ of the sheep. [236] “Sur un cas de Tub. Psorosp. ob. chez l’homme,” _C. R. Soc. Biol._, Paris, 1894 (x), I, p. 201. “Le Parasitisme d. Sarcosp. chez l’homme,” _Bibliogr. Anat._ 1894, p. 79. (5) Vuillemin has also described a case of Sarcosporidia found in the muscles of a man who died from tubercle at Nancy. The author considered that the parasite corresponded to _S. tenella_. (6) Darling[237] (1909) found Sarcosporidia in the biceps of a negro from Barbados. [237] _Arch. Internal Med._, III, p. 183. The Myxosporidia, Microsporidia, Actinomyxidia and possibly the Sarcosporidia may be included within the section *Cnidosporidia* (Doflein), since they possess spores containing polar capsules. Order. *Haplosporidia*, Caullery and Mesnil. The Haplosporidia are a group of organisms having both a simple structure and life-history. The simplicity may represent a primitive condition or may be due to degradation resultant on parasitism, and thus it is possible that the group is not a homogeneous one. The order Haplosporidia was created by Caullery and Mesnil in 1899, and includes parasites of rotifers, annelids (fig. 110), crustacea, fish, prochordates and man. They may be present in the body cavity or alimentary tract, and can also occur in the septum nasi of man, in the nervous system of Cephalodiscus, and in tumours of fish. As the name implies, the spores of the Haplosporidia are simple, without polar capsules, and are uninucleate. In some genera, _e.g._, _Haplosporidium_, _Urosporidium_ (fig. 111) there is a spore-coat or sporocyst which may be elongate or spiny. The developmental cycle of a Haplosporidian, such as _Haplosporidium_ or _Bertramia_, begins with a small, uninucleate cell, often rounded, possessing a cell membrane that may be prolonged into processes. Growth takes place, coupled with an increase in the number of nuclei, so that a multinucleate trophozoite is produced. Later, this multinucleate trophozoite becomes segmented into a number of ovoid or spherical pansporoblasts, which give rise to few (one to four) spores. Such a spore, when set free, begins the life cycle over again.