The central nervous system of heterosymelic individuals of the spider Tegenaria atrica.

This paper presents the results of research on the nervous system in individuals of Tegenaria atrica with heterosymely of walking legs, a pedipalp and the first walking leg. Temperatures alternating between 14 degrees and 32 degrees C every 12 hours were applied as a teratogenic factor in the early stage of embryogenesis. From the thus obtained specimens, histological sections were taken using the paraffin method and then stained. Analysis of the nervous system in individuals with partial heterosymely of walking legs showed no significant changes in the structure of subesophageal nervous mass. In most of the studied individuals with partial and total heterosymely of a pedipalp and walking leg no changes were observed in the relevant parts of the nervous system either, although in two cases a fusion of nerve ganglia was noted, from which the nerves branched off towards the conjoined legs.