抄録
1. In the present experiment, developing eggs were administered of nikotine and subjected to the observation of general growth disturbance as well as of the pathohistological examinations of skeletal muscles (femoral muscle) on the 10 th, 15 th and 20 th day of incubation respectively.
2. Histological findings of muscular tissues can be classified into 3 types of a) those characterized by the diffusive picture of undifferentiation owing to the extremely poor growth of muscular tissues, b) those in which the picture of undiff erentiation is localized and not diffusive the disturbance in the growth of muscular tissues being moderate and c) those in which the disturbance of muscular tissues is slight.
3. Embryos received 1 mg/kg nikotine and examined on the 10 th day of embryonation showed all the three types of changes. While, those received higher doses of nikotine as well as those examined on later days were mostly the types of “a” and “c”. And, moreover, the number of “a” type embryos reduced while that of “c” type increased.
4. Centric multinuclear picture was more remarkable on the embryos of“a” type in which the growth disturbance of muscular fibers was highly advanced and degenerative changes were moderate than on the erpbryos of the other types. This might be a kind of reparative reaction against the above mentioned changes observed on muscular fibers.
5. Incomplete stria formation of muscular fibers was frequently recognized on the embryos of 7 mg group examined on the 15 th day of incubation.
6. Changes into so-called muscular connective tissue in its broad sense were observed on the embryos examined on the 20 th day of incubation.
7. In the present experiment, degenerative or tissue destructive changes observed were diffuse and sporadic having undifferentiated fusiform or stellate cells in their periphery without demonstrating distinct formation of lesions. This, therefore, can be differentiated from the one of so-called embryonic type which can be seen when regeneration of muscular fibers takes place following the degeneration or destruction of muscular fibers.
