If decapod does not pass through zoea stage, is this acceleration? If hypothetical adult retained zoea characters, would this be retardation? Believes obliteration of growth stages frequently due to natural selection. Most interesting points in AH’s letter deal with senile characters. CD attributes them to laws of growth not selection. Explains degraded characters as result of readaptation to simpler conditions. Believes no innate tendency to progressive development exists.

Hopes AH visits F. Hilgendorf’s famous deposit [at Steinheim]. A. Weismann [Einfluss der Isolierung (1872)] makes good use of Hilgendorf’s observations.

Thanks for information about the Atropia.

Comments on additional printing of Expression. Complains about poor quality of plates.

Mentions publication of Expression.

Asks whether children born blind ever frown, shed tears, or contract orbicular muscles.

Congratulates FCD on his anniversary [as Professor at Utrecht].

Exceptional cases of frowning by children born blind have been reported to CD by R. H. Blair [see 8615]; CD asks WB for information and observations on the use of the muscles around the eye by those blind from birth.