iS93-] 113 [Hyatt. 
and regular palingenetic record is assumed to liave been disturl)ed 
by ctetic cliaracters acquired by the larvae.^ 
The gerontic cliai'acters on the other hand and all })araplastic 
as well as then* corresponding phyloparaplastic characters belong- 
to the category of analogies in so far as they are ])urel3' morphie 
resemblances or equivalents. This is clearly shown in the physi- 
ology of all the parts and organs in the anaplastic and paraplastic 
periods, the former being full of hereditary and perhaps also 
acquired power and the latter more or less weakened and reduced 
or worn out by tlie exercise of those powers and the constant 
wear and tear of the surroundings. 
Retrogressive reductions in every form, although often indi- 
cating and accompanying a high degree of specialization, partake 
more or less of the same nature Avhen considered with referen(!e 
to their morphie and accompanying functional attributes, and one 
cannot study such bioplastic phenomena as if they were of the 
same nature and subject to exactly the same laws as progressive 
genetic and ctetic characters. As I have pointed out above and 
in several other publications, thei-e are all degrees of completeness 
in the evolution of the cycle, and it is dependent upon a variety 
of causes whether occui-ring in the ontogeny or phylogeny. If it 
were constant and invariable and independent of the sui louiid- 
ings in the phylum, it would not be so closely parallel to the 
ontogenic cycle, which we know to be subject to great vai'iations 
in accordance with the surroixndings of the individual or sitooies. 
The standard of reference in bioplastology is the ontogenic 
cycle, and this should be studied first in ever}' group. Without 
1 Sucli examples are, correctly speakin<;', not disarrangements of palingenesis 
altiiougli so translated by Haeckel, if I rightly understand his ideas of a confnsed 
record. Cenogenism does occur in such examples in obedience to the same law 
that governs palingenesis, but it occurs through the introduction of ctetic characters 
during the larval instead of in the neanic or ephebic stages, and the crowding back 
of these upon the nepionic and embryonic stages. The use of terms indicating that 
nature has confused or destroyed its own ontogenic records of the transmission of 
characters in certain cases assumes, (1) that these are exceptional cases; (2) that 
cenogenesis is not the normal mode of transmission in certain types in which it 
occurs; (3) that both of these modes of transmission are not afftcted by tachygenesis ; 
all of these implications being erroneous according to the opinions expressed above. 
One can assume a disturbance or jierturbation, or decided change of mode according 
to law, but "destruction," "confusion" or ''falsification" iire subjective terms inappli- 
cable to the objective character of tlie phenomena to which tliey are applied. (See 
also note on p. 78.) 
PROCEKDINGS p.. S. X. H . VOL. XXVI. 8 SePT, 1893. 
