Trigeminal chemosensitivity: Differences in relation to the time of the day

Day-night differences of trigeminal chemosensitivity were investigated in 18 healthy volunteers employing both pain-related cortical potentials and pain ratings in response to stimulation of the nasal mucosa with CO2. Day-night differences were found with N 1 P2 amplitudes, P2 latencies and pain ratings. It is concluded that the time of the day must not be ignored when human chemosensitivity is investigated at suprathreshold levels.      

A combined hand- or power-operated sprayer for fly and mosquito control

A new sprayer is described which was designed in 1945 for the control of adult flies and mosquitoes with insecticides having a kerosene base. This sprayer has been shown in laboratory tests against houseflies, Musca domestica L., and yellow fever mosquitoes, Aedes aegypti L., to be highly efficient for both kill and knockdown and to achieve a particularly rapid knock-down of mosquitoes.
The sprayer can be operated with a hand pump or connected to a supply of compressed air. Air consumption is very low and when the sprayer is power-operated, optimum biological efficiency is obtained at 20 lb./sq.in. air pressure. There is no spitting or dribbling from the nozzle and the mist does not settle so rapidly as to cause any appreciable staining of the floor. Although robust it is light, easily manipulated and can be dismantled into component parts for cleaning. It has no adjustments; but the nozzle, which must be machined with precision, is automatically set in its most effective spraying position when screwed home tightly.     

The use of chromosomal data in the systematics of viviparous onychophorans from Australia (Onychophora: Peripatopsidae)

A chromosomal analysis of populations of viviparous Australian onychophorans has uncovered a large radiation in karyotypic form. Chromosome numbers of 18, 26, 30, 32, 33 and 34 were observed, and these classes could be further subdivided on the basis of internal size relationships. Given the practical difficulties with the systematics of this group, the use of chromosomal data promises to be particularly enlightening. This is the first time any karyotypic data have been published for onychophorans since a single species was analysed in 1900.     

Observations on the biology of Apatopygus recens (Echinoidea: Cassiduloida) around New Zealand

The biology of the New Zealand cassiduloid echinoid Apatopygus recens is reviewed in terms of its geographical distribution, sediment relationships, and associations with other echinoids. Observations were also made on the density and size-frequency distribution of an A. recens population at Croisilles* Harbour, Tasman Bay, and on the burrowing and feeding behaviour of specimens from this locality in an aquarium.
A. recens is a rapid and continuous deposit feeder which burrows completely beneath the surface of the coarse sediments with which it is characteristically associated. The construction of a respiratory burrow to the sediment surface was not observed and the species appears to rely entirely on an adequate interstitial water flow for its respiratory requirements. Two 24 mm long specimens each defaecated an average of 0·76 g dry wt of sediment/h which at the Croisilles Harbour habitat was equivalent to a population ingestion rate of about 7·6 g dry wt of sediment/m²/h.