1Hippocampal slices have been used to assess the sensitivity of the CNS to adenosine and yaminobutyric acid (GABA) in diabetes. The effects of adenosine, 2-chloroadenosine, GABA, muscimol and baclofen were studied on orthodromic synaptic potentials recorded in the CAl region of slices taken from normal rats or animals made diabetic by the injection of streptozotocin. 2 In diabetic animals the sensitivity to adenosine was increased 4 fold compared with normal rats. The potency of 2-chloroadenosine was unchanged. 3 The nucleoside transport inhibitor, hydroxynitrobenzylthioinosine (HNBTI), increased the potency of adenosine in slices from normal rats but not in slices from diabetic rats. 4 No change was observed in the potency of GABA or muscimol, although a small but significant decrease was detected in the ECM value for baclofen.5 Treatment of diabetic animals with insulin restored the potency of adenosine to control levels. 6 It is concluded that the diabetic state is accompanied by substantial changes of adenosine sensitivity due to the loss of nucleoside uptake processes. Secondary neurochemical changes followingfrom this in human diabetic patients may contribute to the reported behavioural changes.

1. Further details of the staining of various organs by Gomori's phosphatase technique have been given. 2. A modification of the technique which involves adding sodium alizarin sulphonate to the substrate mixture has been described. 3. A description has been given of the distribution of phosphatase in regenerating bone. 4. It has been found that phosphatase does not appear to be associated with the calcification of the hen's egg. 5. Phosphatase appears to play some part in the secretion of the shell of certain molluscs. 6. The intensity of phosphatase staining of kidney and adrenal was found to be undiminished in scurvy, but the periosteum and regenerating bone were found to stain less intensely than normal in scorbutic animals.

A new technique has been described for the estimation of the power of a substance to accelerate the healing of bone. It has been found by this method that neither vitamin C nor calcium glucono‐galacto‐gluconate in the doses given accelerates the healing of bone in rats on an adequate diet when injected subcutaneously. On the other hand, it has been found that calcium ascorbate injected subcutaneously into rats does statistically increase the amount of bone regenerated by the end of 7 days. The vitamin C used for these experiments was Redoxon, Roche, and I am greatly indebted to Roche Products Ltd., not only for the vitamin C, but also for making the calcium ascorbate specially for this work at my request.