In previous papers (Roberts, 1962 a, b) the earthworm's rapid response, mediated through the giant-fibre reflex, was described and analysed. In the course of these experiments it was noticed that in the early stages of repetitive stimulation successive responses do not remain the same size but show a marked tendency to increase in magnitude. This staircase effect is particularly pronounced in f...

The complete nucleotide sequence of the gene for chain c of hemoglobin of the earthworm Lumbricus terrestris has been determined. The sequence of 4037 base pairs (bp) includes about 310 bp of 5'-flanking sequence and 110 bp 3' to the poly(A) site. Comparison of cDNA and genomic sequences shows four silent differences in codons that suggest the presence of at least two genes. The coding sequence...

The complete dissociation of the hexagonal bilayer structure of Lumbricus terrestris hemoglobin (3900 kDa) at neutral pH, in the presence of urea, guanidine hydrochloride, sodium perchlorate, potassium thiocyanate, sodium phosphotungstate, and sodium phosphomolybdate, followed by gel filtration at neutral pH on Sephacryl S-200 or Superose 6, produced two fragments, II (65 kDa) and III (17 kDa);...