The activity of larvae was directly and linearly proportional to normal temperatures. Prolonged desiccation was extremely lethal to infective larvae. Very limited random lateral movement occurred in turf, being more pronounced in the presence of faeces. Heavy downflows of water caused severe mortalities but did not affect the rate of movement of surviving larvae through the soil. or more, although most larvae remained in the upper 2 in. axei and T colubriformis were able to penetrate soil to a depth of 12 in. Laboratory experiments indicated that third-stage larvae of T. As I was closely associated with David Keilin and in almost daily contact with him for just on forty years, it is natural that the following account will to some extent reflect my own interests and those aspects of his personality which became manifested during long and intimate contact both in private life and collaboration in scientific and administrative work. In the brief survey of his biochemical work I have made much use of summaries and reports written by Keilin himself and I have often given the essence of lines of work summed up in his own words which express his conclusions with the elegance, lucidity and brevity characteristic of his style.

That bearing on parasitology will be considered in some detail, whereas the later, more biochemical, work will be considered briefly as fuller accounts of it have already been given by E. It is, consequently, not possible for one person to deal adequately with all aspects of his work and in this appreciation of the man and his scientific achievements the main emphasis will be on his biological work. These activities extended from descriptive morphology of protists, fungi and insects to the biochemistry of respiratory enzymes and metallo-protein compounds. The sudden death on 27 February 1963 of David Keilin deprived the scientific world of a biologist the span of whose scientific activities is unlikely to be equalled, much less excelled, in the future.

Callan method all stages rar