Variable response of spleen to Ehrlich's tumor according to the physical form (ascitic or solid) of the tumor

Summary This study confirms the absence of splenomegaly in mice carrying Ehrlich's ascites; however, it reveals the presence of marked splenomegaly in mice bearing the same tumor in the solid state. Thus, the physical form of the tumor is an important factor when evaluating the host's response toward Ehrlich's tumor.Supported in part by a grant from the National Cancer Institute (CA 17944-3).     

Chemical attraction of the eastern yellowjacket,Vespula maculifrons (Hymenoptera: Vespidae)

Summary Workers and queens of the eastern yellowjacket,Vespula maculifrons, are attracted to the artificial long-range attractant pheromone of the predaceous pentatomid,Podisus maculiventris. A 11 mixture of linalool or -terpineol and (E)-2-hexenal is as attractive toV. maculifrons workers as the pheromone.We thank A.S. Menke of the Systematic Entomology Laboratory, USDA, for identifying the yellowjackets. Mention of a company name does not imply endorsement by the US Department of Agriculture.     

Shingle-back lizards crush snail shells using temporal summation (tetanus) to increase the force of the adductor muscles

Summary During the crushing of hard objects, the adductor muscles ofTrachydosaurus are activated in an unfused tetanus with the tetanic pulses of the several motor units occurring in synchrony.