284 II. I.YNDHUR8T DUKK. 



EXPLANATION OF PLATES 15 and ]G, 



Illustrating Mr. H. Lyndhurst Duke's paper on " Some 

 Observations on a New Grregarine (Metamera scliu- 

 bergi nov. gen., nov. spec.)." 



PLATE 15. 



[Figs. 1 and li were dniAvn from living- animal. fi<^s. 3 and 4 from 

 preparations fixed with alcohol and acetic acid and stained with 

 Schuberg's modificaticm of Mayer's acid carmine. Figs. .5, fi. and 16 

 are diagramimitic. Figs. T-lS were fi.ved with Gilson's fluid and stained 

 with Heidenhain's iron-luematoxyliu. All tliese figures were drawn 

 with Zeiss oc. 6, obj. 2 mm. apochroniatic. Figs. 9, 10, 11. and 17, 18 

 are to scale at magnification of 2000. Figs. 12. l.'>. 14 are dniwn on 

 a slightly smaller scale. J 



Fig. 1. — Living sporont expressed tln-ough anus of leech. 



Fig. 2. — Same sporont as Fig. 1, showing bubble-formation. 



Fig. 3. — Cephalont with epimerite embedded in fragment of liost- 

 tissne. 



Fig. 4. — Showing optical section of epimerite. 



Fig. 5. — Diagram of structure of epimerite. etc. 



Fig. 6. — Diagram of sporont with cuticular j^ad on epimerite. 



Fig. 7. — Nucleus of trophozoite. 



Fig. 8. — Nucleus showing fragmentation of chromatin masses and 

 exti'usion process of karyosonie. 



Fig. 9.— ^Sporont nxicleus showing earliest appearance of the " achro- 

 matic mass," with fragmentation of the karyosonie. 



Figs. 10 and 11. — Successive sections of another nucleus showing 

 slightly later stage than fig. 9. 



These three figures (9, 10 and 11) are drawn from same cyst. 



Fig. 12. — First division of sporont nucleus showing at (o) the ring 

 arrangement l^eginning at the pole ; also the streaks of chromatin and 

 the spindle-fil)res in optical section. The two poles are respectively at 

 the extreme upper and lower focus. One of the chromatin streaks is 

 seen running into the polar aggregation. 



Fig. 13. — An early cyst, containing two associated individuals, with 

 remains of epimerites seen at the centre. Nuclei at stage of fii-st 

 division. In upper animal the polar aggregation and the chi-omatiu 

 streaks are very marked. (Combined from two successive sections.) 



