THE SPOROZOA 267 



the blood-corpuscle in length when adult, and is bent on itself within 

 it in a characteristic manner, like the letter U. A large number of 

 species from reptiles (Chelonia, Lacertilia, Ophidia, Crocodilia), of which 

 the commonest are H. lacazei (Labbe"), from Lacerta agilis, and H. stepanovi, 

 Danil. (Fig. 77), from Emys lutaria and Cistudo europaea. H. magna 

 (Gr. et Fel.), occurring in the frog, Sana esculenta, is perhaps the macro- 

 gamete of Lankesterella ranarum or L. monilis. Three species have recently 

 been described from fishes : H. delagei, Lav. et Mesn., from Raia punctata 

 and R. mosaica, H. simondi, Lav. et Mesn., from the sole, and H. bigemina, 

 Lav. et Mesn. (Fig. 72), from two species of blennies. A doubtful species 

 has even been described by Eisen under the name H. nasuta, from the 

 blood of an Annelid (Eclipidrilus frigidus). 



SUB-ORDER II. ACTSTOSPOREA. 



The trophozoite is an amoeboid haemamoeba, or is of simple body- 

 form, and is typically endoglobular throughout the schizogonous cycle. 

 An alternation of hosts is known in many instances to occur ; the 

 schizogony takes place in the vertebrate host, usually a warm-blooded 

 animal (bird or mammal) ; the sporogony takes its course in an 

 invertebrate host, which is an arthropod in all cases hitherto observed. 



Genus 4. Plasmodium, Marchiafava et Celli, 1885 (syn. Haemamoeba 

 auct.). The haemamoebae contain granules of melanin-pigment. The 

 merozoites are oval in form, arranged in a single group round a central 

 residual body. Gametocytes spherical. Two species generally recognised, 

 both parasitic upon man ; see above, p. 243. To this genus also Liihe 

 refers the form discovered by Kossel in apes, and named by Laveran 

 Haemamoeba kochi. 1 Genus 5. Laverania y Gr. et Fel., 1890 (syn. 

 Haemomenas, Ross, 1899). Trophozoites and merozoites as in the last. 

 Gametocytes crescent -shaped. One species, L. malariae, Gr. et Fel. 

 (syn. Haemamoeba s. Haemomenas s. Plasmodium praecox, etc.), parasitic 

 in human blood ; see above, p. 243 (Fig. 68). Genus 6. Haemoproteus, 

 Kruse, 1890 (syn. Proteosoma, Labbe", 1893). Trophozoites and merozoites 



1 Schaudinn, in his monograph on the tertian parasite [94a], unites forma here 

 placed under the three genera, Plasmodium, Laverania, and Haemoproteus, in one 

 genus, to which he gives the first of these three names ; since he does not consider 

 the differences in the form of the gametocytes to be an adequate generic distinction. 

 The genus Plasmodium in his revision contains the following species : 



(1) P. malariae (Lav.), quartan parasite of man. 



(2) P. vivax (Gr. et Fel.), tertian parasite of man. 



(3) P. immaculatum (Gr. et Fel.), parasite of human pernicious malaria. 



(4) P. praecox (Gr. et Fel.), the "Proteosoma" parasite of birds. 



(5) P. kochi (Lav.), from the blood of apes. 



The genus Halteridium Schaudinn considers to be distinct, but he declares that it 

 should be named Haemoproteus, so that the halter-shaped parasite of birds stands as 

 Haemoproteus danilewskyi (Gr. et Fel.) ! 



The confusion in the scientific names of these parasites is now so great as to lead 

 to the remarkable result that the popular names commonly given to them furnish 

 more distinctive and intelligible appellations than the ever - changing "correct" 

 taxonomic nomenclature." 



