\"Permitmetotakethisopportunitytoexpressmysincereregretathavingcommittedtwograveerrorsinthelasteditionofmy’OriginofSpecies，’
inmyallusiontoyoursandProfessorCope’sviewsonaccelerationandretardationofdevelopment。IhadthoughtthatProfessorCopehadprecededyou;butInowwellrememberhavingformerlyreadwithlivelyinterest，andmarked，apaperbyyousomewhereinmylibrary，onfossilCephalapodswithremarksonthesubject。ItseemsalsothatIhavequitemisrepresentedyourjointview。Thishasvexedmemuch。IconfessthatIhaveneverbeenabletograspfullywhatyouwishtoshow，andIpresumethatthismustbeowingtosomedulnessonmypart。\"
Lastly，itmaybementionedthatthischeapeditionbeingtosomeextentintendedasapopularone，wasmadetoincludeaglossaryoftechnicalterms，\"givenbecauseseveralreadershavecomplained……thatsomeofthetermsusedwereunintelligibletothem。\"TheglossarywascompiledbyMr。
Dallas，andbeinganexcellentcollectionofclearandsufficientdefinitions，musthaveprovedusefultomanyreaders。]
CHARLESDARWINTOJ。L。A。DEQUATREFAGES。