\item[p. 236] (Frank Piessens). The statement, ``It would be incorrect to assume in general (although it is true in familiar examples) that every node of $\Tsc$ is a limit of a diagram in the graph of $\Ssc$'' is wrong. The reason is that $\Tsc\op$ is a full subcategory of the category $\Fun(\Ssc,\Set)$ (to be precise, that should be the free category generated by the graph underlying $\Ssc$) and every functor is a colimit of representables and, hence, in $\Tsc$, every functor is a limit of them. Thus every object of the theory is a limit of a diagram built from the objects and arrows of $\Ssc$. \item[p. 387] (Nico Verwer). The solution to Exercise 4 of 8.3 contains several errors. The right hand label of the diagram should be $<f,g>$, the lower left corner of the diagram should be $B$ and the $f\x g$ in the displayed line that begins $G(X)=\ldots$ should also be $<f,g>$. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++