1897.] : Zoology. 721 
Many of the preceding mineral molecules were qnis coupons in com- 
position, and it is still molecules 
arose under conditions restraining the activity of oxygen. Seed forms 
of organic substance may have first appeared—simple carbon com- 
pounds. These would serve as the basis of more complex molecules, 
and there may have been a long-continued process of deoxidation and 
formation of higher carbon and nitrogen compounds until true organic 
matter appeared and the chemistry of life came fairly into play. 
Further the author remarks that “ the conditions favoring the devel- 
opment of organic material were transitory, and no longer exist. Or- 
ganic chemistry emerged from a vitally active stage of inorganic 
chemistry. It could not well arise from the existing passive stage of 
inorganic chemistry.” (Proceeds. Acad. Nat. Sci., Phila., 1897). 
The Life Cycle of the Coccidii of Arthropods.'—During the 
course of his researches on the Sporozoa of Arthropods Liger came to 
the conclusion that the form that has been described under the name 
of Eimeria is not an independent animal but only a form in the life 
cycle of Coccidium. In the intestine of myriopods and of insects, em- 
bracing species of Himantarium, Stigmatogaster, Lithobius, Sapte 
and Tipula, two forms of the parasites were always present. In the 
myriopods there could be recognized, (1) cysts of Eimeria, growing and 
mature, enclosing numerous sporozoids regularly disposed and envel- 
oped in a delicate wall; (2) free active sporozoids, that might be seen 
in the process of becoming detached from those just noted ; (8) intra- 
cellular forms, among which one might recognize all the transitional 
forms between the sporozoids just noted and the encapsuled form mark- 
ing the end of the period of growth; (4) encapsuled forms, free or still 
intra-cellular and showing the beginning of the division of their con- 
tents into four granular masses; (5) these same cysts in a mature con- 
dition with four oval spores each containing two sporozoids. 
An examination of the excrement of a Himantarium that was later 
found infested showed the existence there of the cysts of Coccidium, 
which are to be considered as giving rise to Eimeria. The sporozoids 
of Eimeria were found incapable of existing in water. As further sup- 
porting his position he cites the fact that when Coccidium is present, so 
is Eimeria, and when one is absent, so is the other. This coéxistence 
of the two forms in the same animal has been long known, and it is 
added that an arthropod has never been found containing a Coccidium 
with lasting spores that did not also harbor an Eimerian form. 
1 L. Liger. ©. R. Acd. Sci., CXXIV, pp. 966. 
