An unusual receptor in the octopus

The epithelium of the rim of the octopus sucker is the site of several different types of primary receptors. One is a non-ciliated cell with unusual characteristics. (1) The surface of the cell is extremely irregular with finger-like extensions of cytoplasm, especially far reaching in the basal region. (2) The slender neck contains a canal whose apical opening is in contact with the environment. This canal is lined with microvilli and contains granular material in an electron-dense matrix. (3) Patches of presumed glycogen granules occur throughout the cell, being especially abundant in the outer reaches of the cytoplasmic extensions. Their presence, together with numerous mitochondria and free ribosomes, indicate a high intrinsic metabolism. (4) Small fascicles of microtubules are randomly situated throughout the perikaryon. They gather into a coherent system of larger and larger bundles which ultimately enter the axon leading from the cell. This axon extends some distance in the basal region of the epithelium before crossing the subepithelial space to enter the infundibular muscle. Possible functions of this cell are discussed. On the basis of its specific position on the sucker and its intrinsic morphology we suggest that it is a mechanoreceptor involved in shape and/or negative pressure discrimination.     

Scrotal circumference measurements in 764 beef bulls.

A total of 764 breeding soundness examinations was conducted on beef bulls utilizing the method of examination and criteria for classifying bulls of the Society for Theriogenology. In addition to this examination each bull was subjected to scrotal circumference measurement and to weighing. Classification of the bulls according to breeding soundness potentials was as follows: 88% of the bulls were satisfactory potential breeders, 8% of the bulls were questionable potential breeders and 4% of the bulls were unsatisfactory potential breeders. The proportions of bulls in each classification; satisfactory, questionable, or unsatisfactory; were not different among the four breeds evaluated. The majority of bulls evaluated in this study were between 14 and 36 months of age and weighed between 900 and 1500 pounds. For the ages and weights evaluated, scrotal circumference measurement variances were not closely related to age and weight differences. There was a tendency shown for “Questionable” and “Unsatisfactory Potential Breeders” to have smaller scrotal circumference measurements. The study indicates that Angus, Charolais, Horned Hereford and Polled Hereford bulls of breeding ages and weights should have scrotal circumference measurements of at least 32 centimeters in order to be classified as “Satisfactory Potential Breeders”.