iSgS-] 301 [Hyatt. 
England, nnd Wiii'tenberger in Germany, have admitted their 
existence, ami the last redescribed them. Wurtenberger ^ has 
admirably described the phenomena of bioplastology as they occur 
among Ainmonitinae, and correctly interpreted the law of tachy- 
genesis and its action in these forms, but failed to quote either 
Professor Cope or the author. This omission was not so remark- 
able as the fact that Neumayr and some other investigators, after 
they had received the printed records of the work done in the 
same direction in this country, continued to qiiote Wiirtenberger 
as the sole discoverer of these phenomena and of the law of 
tachygenesis. Wiirtenberger's work was apparently independent, 
;iiid it has liiglier value on that account, but it needs rectification 
from an liistorical [>'jint of view. 
i\[yown researches have led mi' lo the conviction that still finer 
classiHcation and minuter subdivision of the development:d jihe- 
iiomenaof the nepionic, neanic, and ephebic st;iges are necessary, 
and for obvious reasons I shall take my illustrations Avholly from 
the Cephalopoda. 
The nomenclature of the youngest of the epembryonic stages, 
or nepionic, is, naturally, the first to be considered. Tiie term 
used by Buckman and Bather, 'djrephic," derived from Pp€4>ikos, 
would have been an ;ipi)i-opriale substitute for nepionic,- but 
unluckily it was not used in 1SS8. The latter h.is been used 
by authors on this side of the .Vthmtic in several essays, and is 
found in the (Century dictionary and therefore consistently with 
the principle adoi)ted by Buckman and Bather and myself, to 
de|)art from established terms as little as practicable, it should be 
per|)etuated. It has not deserved the sharp criticism of these 
authorities, since it is not an " impossible corruption of the 
Greek." It is a convenient term, and not worse etymologically 
than one that those authors themselves supported, and another 
which they proposed. P2mbryonic has a precisely parallel history, 
there being in Greek no authority for the use of the termination 
"' ic," and this is adopted by them without comment. Hypostro- 
phic, derived from vTroo-Tpo<j>T]', which also has no authority for its 
termination in "ic," was one of the terms proposed by them. So 
1 Stiulien uber die stammesgeschichte dei- animoniteii. VAn geoloyisclRT hcwcis fur 
die Darwin'sche theorie. Leipzig, 1880. 
2 Originally taken from vtiiryos t)ut there is a funu vririov. 
