50 Years Ago

Normal tissue growth requires that cells should recognize each other and stop growing or moving at the right time and place. Understanding how this regulation is achieved is of fundamental importance. A priori one might expect that some kind of chemical signal passes from cell to cell. This is certainly the simplest explanation of the phenomenon of contact inhibition — cells stop moving and dividing when they come into contact with each other ... Loewenstein and his collaborators ... have shown that at regions of cell contact, junctional surfaces, in several tissues cellular substances diffuse rather freely from the interior of one cell to that of the next ... Thus a quite large molecule could act as a signal for contact inhibition ... These experiments ... suggest that normal growth and differentiation of tissues depend on a flow of material from the interior of one cell to that of another.

From Nature 17 June 1967

100 Years Ago

M. G. Daressy has been writing concerning the long-disputed question as to the identity of one of the animals which the old Egyptians selected as the symbol of their malevolent deity, Set or Seth. Among creatures suggested as intended by the Egyptian artists have been the jackal, hare, oryx, and okapi, but all these assignments have been abandoned ... M. Daressy argues that the Set animal is really a creation of the imagination ... so it is futile to search for the creature in either the existing or fossil fauna in Africa ... It may be that the animal was very scarce, and that after its association with the detested deity it was exterminated by the Horus-following, orthodox Egyptians.

From Nature 14 June 1917 Footnote 1