Hyatt.] bb [Aprils, 
be (.k'sii;ii:itcHl by tlie term I)i<»i'i.Asroi>o(;Y from Pios, life, mikI 
irXao-Tos, meaning moulded or formed.^ 
IJiogeny lias been used in extra scientific literature by Fiske 
with the same meaning as bioplastology, and liaeckel lias named 
the law of embryonic and ancestral correlation the law of biogene- 
sis, but there is a strong objection to both of these. Biofjenesis 
is the name given to the theory of the origin or genesis of life 
from lite in contradistinction to the assumption of spontaneous 
generation, or abiogenesis, and has a well established place in 
scientific literature. Therefore, while the law of correlation of 
the stages of development and those of the evolution of the phy- 
lum may, if one chooses, be called a law of biogenesis, it is more 
accurate to consider it a law of correlation in bioplastology, or 
better still the law of palingenesis, since it is the law of the regular 
repetition of ancestral characters ; and this exactly expresses 
what the discoverer (Louis Agassiz) saw and described. 
This branch of research is necessarily founded upon the laws of 
groAvth and genesiology and ctetology, but it is directly occupied 
with the study of the morphogenesis of individuals and types, 
especially their fossil remains, among which evidence cm be 
gathered, not only from the relations of the epembryonic^ ])eriods 
of ontogeny and the corresponding periods of phylogeny, but from 
the actual succession of forms in time. 
This evidence among cephalopods, brachiopods, corals, pclecy- 
pods, and other animals having hard parts, which are present in 
all stages of ei)embryonic life of well preserved fossils, is destined 
to furnish more complete series of facts in some directions than 
can be obtained by the study of recent forms alone or by experi- 
mentation. The limitations of time cannot be overcome by the 
observer of existing life, and the study of the natural succession of 
forms in any genetic line from the beginning to the end of the 
' Bioplasm, bioplast, bioplastic have already been used by Beale and others for the 
living- cell and its contents but the term bioi)lastology has not been used nor have the 
names proposed by Beale been generally adopted. If they were, bioplasniology would 
cover the requirements of students of such phenomena and there is already in use 
plasniology with about the same meaning, and histology for the descriptive side of the 
study of cellular structures. 
■ The prulix p.ira, past or beyond, cannot br used hero for fear of confusion with 
paragerontic, etc., and I have therefore taken eiri and embryonic, meaning all stages 
of development after the embryonic, including the senile. 
