AUTTFICIAL PAETH ENOGENESIS IN' ECIIINITS ESCIJEENTIJS. 551 
Fig. 12. — Partlienogenetic Echinus; dorsal aspect. Still retains 
portion of the pluteus skin, through which some of the spines are seen 
l^rojecting dorsally. X 100. 
Fig. 13. — Young Echinus shortly after metamorphosis; ventral 
aspect. Raised from egg fertilised with sperm, x 100. 
Fig. 14. — Young partlienogenetic Echinus ; ventral aspect. Loeh's 
method. X 100. 
Fig. lo. — Metamorphosing partlienogenetic Echinus. Loeh’s 
method. X 100. 
Fig. 10. — Partlienogenetic pluteus showing Echinus-rudiment, x 100. 
PLATE 32. 
Fig. 17. — Parthenogenetic pluteus ; 25 days ; ventral aspect ; Echi- 
nus-rudiment showing. X 50. 
Fig. 18. — Pai-thenogenetic pluteus; 20 days; veiitro-lateral aspect. 
X 50. 
Fig. 19. — Pai-thenogenetic pluteus; 22 days; ventral aspect ; showing 
Echinus-rudiment. X 50. 
Fig. 20. — Parthenogenetic iiluteus ; dorsal aspect ; 4 days, x 50. 
Pig. 21. — Parthenogenetic pluteus; dorso-lateral aspect; 5 days. 
X 50. 
Fig. 22. — Parthenogenetic iiluteus; 22 days ; ventral aspect. Avery 
abnormal form freijiiently turning iiji in cidt lire- jars. X 50. 
Fig. 23. — Parthenogenetic pluteus ; dorsal asjiect ; much degenerated. 
22 days, x 50. 
