The histochemistry of the neural cells was studied in the submandibular ganglia of 5 Callithrix jacchus (3 males and 2 females) and 4 Callithrix penicillata (2 males and 2 females). These cells contain neutral mucopolysaccharides, nucleoproteins and lipidic material, but are apparently devoid of glycogen. It was impossible to demonstrate in them any reactivity for UDPG-GT, phosphorylases, ATPase at pH 6.3, leucine aminopeptidase and alanyl amino-peptidase. The reaction for the other searched enzymes was as follows: weak (F-16-P Aid and cytochrome oxidase), weak to moderate (ADH, 6-P-GDH, ICDH, SDH, MDH, α-GPDH and β-OHBDH), moderate (G-6-PDH, F-1.6-PA, LDH and GDH), moderate to strong (ATPase at pH 7.4, nonspecific esterase and acid phosphatase) and strong (G-6-PA, NADH2-TR, NADPH2-TR, ATPases at pH 8.5 and 9.4 and alkaline phosphatase