Howard E. Evans

Autonomic innervation of the tongue: a horseradish peroxidase study in the dog.

Autonomic ganglia have been found along the lingual nerve in the rostral two-thirds of the canine tongue and along the glossopharyngeal nerve in the caudal glandular third of the tongue [4,17,18]. A 30% horseradish peroxidase (HRP) solution was injected throughout these ganglionated areas in order to identify the origin of the preganglionic fibers to the lingual ganglia. These injections resulted in ipsilateral retrograde labeling of small multipolar neurons in the lateral reticular formation of the medulla oblongata. The same injections labeled neurons in the ipsilateral cranial cervical ganglion, but preganglionic sympathetic neurons in the thoracic spinal cord were not labeled. These findings indicated that the lingual ganglia consist of parasympathetic neurons which receive preganglionic projections from the medulla. The lingual preganglionic neurons were located within the nucleus reticularis parvicellularis and, in this location, were co-extensive with salivatory neurons that labeled after HRP injections in the mandibular and sublingual salivary glands. A degree of somatotopic organization within the lingual preganglionic group was indicated by the results of regional injections of enzyme and was confirmed by performing unilateral chorda tympani and glossopharyngeal neurectomies prior to extensive bilateral injections of HRP.

Ossification of the Atlas‐Axis Complex in the Dog*

Skeleton preparations of 200 Beagles of known age, ranging from embryos at 28 days of age to 10 year old adults were studied. Preparations of gross specimens were examined with the aid of Alizarin red staining, binocular dissection and histological sections. Ossification centers for the components of the atlas and axis were identified and followed to their fusion. The developmental ossification sequence for these bones is described and compared with that of other similar studies in other species.

A Review of Nesting Behavior of Digger Wasps of the Genus Aphilanthops, With Special Attention To the Mechanics of Prey Carriage

The digger wasp genus Aphilanthops is divisible into three subgenera. Two species of the subgenus Aphilanthops are known to prey upon winged queen ants of the genus Formica. One of these species, frigidus, has been studied in some detail by WHEELER and by the present writer. In carrying the ant, the female grasps the antennae with her mandibles and holds the ants body beneath her with her legs. The ants are stored at the bottom of the burrow, where the wings are removed; later they are moved to cells deeper in the soil. Two or three ants are used per cell; when the cell is fully provisioned the egg is laid on the top ant and the cell closed. WHEELER reported that the cells are provisioned progressively, as the larva grows, but the present studies indicate that this is not the case. Members of the subgenera Clypeadon and Listropygia prey upon worker ants of the genus Pogonomyrmex. Some information is available on six species of Clypeadon and the one known species of Listropygia, but the only detailed studies are those made by the writer on A. (Clypeadon) haigi. The general details of the nesting behavior of this species are much as in frigidus. Storage of ants in the burrow occurs, and 14 to 16 ants are supplied per cell. The ants are captured and stung at or inside the entrances to their nests. They are carried fastened to the apical segment of the wasps abdomen by the base of the ants middle and hind legs, thus leaving the mandibles and legs of the wasp free. The peculiar ant-clamp formed by the apical body segment of members of the subgenera Clypeadon and Listropygia is unique among digger wasps. Apparently it arose as a modification of the simple pygidial plate of members of the subgenus Aphilanthops, which is probably used for packing soil in the burrow as it is in other digger wasps. The pydigium and hypopygium of the species of Clypeadon are biconcave and have various processes which seem to be well fitted for clamping on to the middle and hind coxae of the ant (probably with the aid of blood pressure or muscular action). In Listropygia these modifications have become quite elaborate. While no one has observed closely the manner of prey carriage in Listropygia, it is possible to postulate how some of the various processes and notches fit into specific structures on the ant to provide a more effective device for holding the ant.

An Ethological Study of the Digger Wasp Bembecinus Neglectus, With a Review of the Ethology of the Genus

[The behavior of the small digger wasp Bembecinus neglectus (Cresson) is described for the first time. The observations were made from June 24 to July 13, 1953, in an area of sandy glacial drift in Pottawatomie County, Kansas. Males were observed June 24- July I walking in small circles on the sand, taking short, hopping flights, and pouncing upon other males and females in attempted matings. Activity in the colony usually started about 9 a.m. and was at its height until 2 p.m. Females were present and engaged in nesting activities throughout the period of observation. The nest is dug by the female in about one hour; the burrow length averaged 11 cm. and the depth of the cell averaged 7.8 cm. The majority of individuals prepared a second cell in the same nest after the first one was fully provisioned. The egg is laid in the empty cell glued at about a 45° angle to the top of the small lump of sand grains, slanted away from the entrance to the cell. The day after oviposition, before the egg hatches, from one to three leafhoppers are brought in and placed head-in, venter-up, beside the egg. After the egg hatches, the larva is fed progressively for two or three days, until the cell is full and is closed off. From 10 to 15 leafhoppers are provided per cell. Two species of leafhoppers were used in large numbers, and one specimen of another species was found (all adults) ; two nymphal Dictyopharidae were found in one nest. The wasp always closes the nest when leaving, and spends little time in the nest when not engaged in provisioning; a final closure is made when provisioning is complete. The known ethology of other species of Bembecinus is reviewed, all species appearing to agree rather closely with neglectus. The unique features in the behavior of Bembecinus are reviewed, and reasons are advanced for considering the resemblances of this genus with the bembicine wasps as due to parallelism in evolution., The behavior of the small digger wasp Bembecinus neglectus (Cresson) is described for the first time. The observations were made from June 24 to July 13, 1953, in an area of sandy glacial drift in Pottawatomie County, Kansas. Males were observed June 24- July I walking in small circles on the sand, taking short, hopping flights, and pouncing upon other males and females in attempted matings. Activity in the colony usually started about 9 a.m. and was at its height until 2 p.m. Females were present and engaged in nesting activities throughout the period of observation. The nest is dug by the female in about one hour; the burrow length averaged 11 cm. and the depth of the cell averaged 7.8 cm. The majority of individuals prepared a second cell in the same nest after the first one was fully provisioned. The egg is laid in the empty cell glued at about a 45° angle to the top of the small lump of sand grains, slanted away from the entrance to the cell. The day after oviposition, before the egg hatches, from one to three leafhoppers are brought in and placed head-in, venter-up, beside the egg. After the egg hatches, the larva is fed progressively for two or three days, until the cell is full and is closed off. From 10 to 15 leafhoppers are provided per cell. Two species of leafhoppers were used in large numbers, and one specimen of another species was found (all adults) ; two nymphal Dictyopharidae were found in one nest. The wasp always closes the nest when leaving, and spends little time in the nest when not engaged in provisioning; a final closure is made when provisioning is complete. The known ethology of other species of Bembecinus is reviewed, all species appearing to agree rather closely with neglectus. The unique features in the behavior of Bembecinus are reviewed, and reasons are advanced for considering the resemblances of this genus with the bembicine wasps as due to parallelism in evolution.]