Summary

Testimonial letter for GRW for position at British Museum.

Summary

Classification consists of grouping beings according to descent from common stocks. Analogies are resemblances between forms not inherited from common stocks. Neither number of species nor grade of organisation should be considered in classification. Admits that caution is necessary in admitting a few species to form a group of rank equal to one containing many species.

Summary

Has no objection to uniting Monotremata and other marsupials but would object to doing so solely on ground that Monotremata consists of only two species. Members of a natural group need not share common character so long as they are linked with those which do. Believes that if every organism that ever lived were collected, a perfect series would be presented. What are reasons that unite Aptera and Diptera?

Summary

Congratulates GRW on appointment to position at British Museum.

Summary

Comments on GRW’s paper [Rep. BAAS (1843): 65–7; Ann. & Mag. Nat. Hist. 12 (1843): 399–412]. CD says by "link" between any two groups he never understood a half-way link, merely one in a long series. Observes that one cannot have a simple species intermediate between two great families. Criticises GRW’s use of circles to represent groups, which leads to thinking that groups are of equal value.

Summary

Cancelled: enclosures to DCP-LETT-869. List of recent and fossil mammalian species of Brazil.

Summary

Cancelled: enclosures to DCP-LETT-869. List of fossil Mammalia from the caverns of Minas Gerais purchased by the British Museum from Claussen.

Summary

Discusses classification of animals. Degree of affinity different for different taxonomic groups. Discusses affinity of Ornithorhynchus or Echidna to reptiles.

Brain of whale is highly developed; on differences among brains of Quadrumana.

Summary

Explains what he means when he attempts a "natural classification", defining his words and using man as a standard; gives examples. Classification of Aptera and Diptera.

Discusses his discharge from the Zoological Society. Is to see Robert Brown about the British Museum position.