PLATE L. 



Illustrating the more important modifications of the nucleus or endoplast and nucleolus or 

 endoplastule as developed among the Infusoria. 



Fig. 



EXPLANATION. 



Simple spheroidal nucleus or endoplast, with enclosed nucleolus or endoplastule, of 

 a collared monad, Codosiga, the same type being distinctive of the majority 

 of the Flagellata. 

 2. A single germinal fragment or spore, with contained endoplast and endoplastule, 

 oi Dictyocysta cassis, x looo (Haeckel). 

 3-5. Modifications of the endoplast of Euglcna viridis.—z, representing the normal 

 form ; 4 and 5, progressive phases resulting in the subdivision of its entire 

 mass into sporular elements x 600 (Stein). 

 6. Fusiform endoplast, with centrally enclosed endoplastule, of Chilodon cuciilliillus, 

 X 480 (Wrzesniovvski). 

 7-9. Various modifications of the endoplast o{ Leptodiscus medusoides (Hertwig). 



10. Ovate endoplast having a reticulate granular consistence, with laterally attached 



endoplastule, of ^««(:/rz/a7«^<j, x 1280 (Maupas). 



11. Subspheroidal endoplast, with numerous enclosed endoplastules, oi Acineta Jolyi, 



X 900 (Maupas). 



12. Spheroidal granular endoplast of Rhizopod /"t'/owya-a tvY^j-*?, x iooo (Leidy). 



13. Twin endoplasts, with connecting cord or funiculus, of iL//'<?«o//?^/<zi'«o/<z, x 4S0 



(Wrezsniowski). 



14. Endoplastic system of Loxodcs rosinim, consisting of numerous spheroidal endo- 



plasts with both enclosed and externally developed endoplastules connected 

 together by a thread-like funiculus. In some instances, a a, the external 

 endoplastules are attached to the funiculus, x 600, and treated with acetic 

 acid and iodine (Wrzesniowski). 



15. Twin endoplasts with connecting funiculus oi Litoiiottcs diapltanus after treatment 



with acetic acid and iodine, x 600 (Wrzesniowski). 



16. Endoplast of Chilodon cucullullus with both an internally developed and laterally 



attached endoplastule, x 400 (Wrzesniowski). 



17. Twin endoplasts, with laterally attached endoplastules, of i'//V/;o/r/c/;(Z aciilcata, 



X 600, + acetic acid (Wrzesniowski). 

 iS. Endoplastule of Pleiironema chrysalis after treatment with acetic acid (Biitschli). 



19, 20. Modifications of the endoplast of Nyctotherus cordiformis. — 19, normal form, 

 with laterally attached endoplastule ; 20, endoplast become greatly enlarged 

 and metamorphosed into an elaborately convoluted coil (Stein). 

 2!. Band-like endoplast with a, investing membrane and b, b, contained endoplas- 

 tules of Vorticclla microstoma, x 450 (Stein). 



22, 23. Band-like endoplasts of Carchcsium polypinum, subsequent to conjugation ; at 

 22, earlier phase with nunierous enclosed endoplastules ; at 23, more 

 advanced stage in which the internal substance has become separated into 

 as many as ten germinal masses which arc held together only by the delicate 

 bounding membrane of the originally continuous and homogeneous endo- 

 plast, X 1000 i^Greef). 



