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The relatively large, but superficially similar, Lerista macropisthopus, L. connivens, and L. lineopunctulata differ in bodily elongation and limb reduction, inhabit sandy areas, and move under sand. Visual analysis and computer-generated excursion and curvature graphs show that each species moves differently on smooth and rough surfaces, on surfaces with and without nails, and in channels. The reduced-limbed quadruped, Lerista macropisthopus walks frequently, using its four clawed limbs, whenever traction is available. Its undulating body curves uniformly but never generates slide-pushing curves. The biped L. connivens walks with its hindlimbs, although less frequently, and/or oscillates its tail in propelling its relatively stiff, short body. The biped L. lineopunctulata rarely uses its hindlimbs but always undulates body and. tail. It can use single nails in cam-follower progression. L. macropisthopus and L. connivens walk well in channels with rough bottoms, but only L lineopunctulata uses tunnel concertina to travel in channels with smooth bottoms. Friction of body surfaces dragged and of those transmitting propulsive forces is critical to these lizards and explains the division of movement into slow and rapid progression rates. Animals that have clawed limbs, no matter how reduced, use them. Body and tail generally are used differently. The tail may be flipped anteriorly to facilitate concertina. In nail arrays, travel is by simple, never by lateral, undulation. Apparently distinct motor coordination patterns are associated with differences in morphology, habit, and habitat. © 1994 Wiley-Liss, Inc.

Spatial and temporal variation in critical life history traits differ markedly between two co-occurring, rare and endangered annual plants, Gilia tenuiflora arenaria and Chorizanthe pungens pungens, that have restricted, but overlapping geographic distributions in coastal habitats of central California, USA. Environmental variation was extreme during the 6-year study (1997–2002), with the greatest differences between an intense wet, warm El Nino year (1998), followed by a very dry, cool La Nina (1999). Both species have similar increases in adult survival and seed set with wetter, warmer weather in spring, but they differed in other traits: more Gilia germinated in years with high rainfall and temperature, while more Chorizanthe germinated in dry, cooler years; Gilia abundance increased with the number of years since the previous large El Nino event, while Chorizanthe abundance declined; and Gilia abundance was independent of the previous year’s seed set, while Chorizanthe density was directly related to the previous year’s seed set. The strong negative associations of Chorizanthe abundance with warm, wet weather and with time since the previous El Nino probably reflect the particular sequence of annual weather patterns from 1997 through 2002, especially the extremes in 1998 and 1999. Since it germinates readily in most years under a wide range of winter conditions and does not develop a long-lived seed bank, Chorizanthe seedling abundance reflects recent additions and depletions of its seed bank, rather than prevailing weather, per se. In contrast, Gilia seeds may remain in the seed bank for many years, until relatively rare winter conditions trigger significant germination. These species-specific demographies enhance persistence and coexistence of these species, but the mechanisms differ from each other and from those described for annuals in other highly variable environments.

Fossorial lizards differ in morphology from their surface-dwelling relatives. The Australian sphenomorphine skink genus Ctenotus consists of surface-dwelling species, and is closely related to the genus Lerista, which includes both surface-dwelling and fossorial species. Sand-swimming represents the derived condition and has evolved independently in several lineages of Lerista. The heads of lizards in the two genera differ in shape (blunt snout for Ctenotus versus wedge-shaped for Lerista) and in length relative to the body (approximately 20% of snout-vent length for Ctenotus versus 12% for sand-swimming Lerista). Do these specializations affect the sizes or types of prey that can be consumed by Lerista? We compared prey-handling by Ctenotus and Lerista to correlate morphological differences with differences in prey-handling ability, and to distinguish the effects of snout shape and head length. Feeding trials included three categories of insect prey that the lizards normally eat: soft-bodied larvae (Lepidoptera), hard-bodied larvae (Coleoptera), and roaches (Blatoidea). In comparisons based on the mass of a prey item relative to the mass of a lizard, Lerista had longer handling times for all prey categories and were limited to smaller prey than were Ctenotus. However, when comparisons were based on the length of prey relative to the length of a lizard's head, Lerista ate some elongate prey as fast or faster than did Ctenotus, and both genera successfully swallowed prey more than twice the length of their own head. Thus, the differences in prey-handling performance of Ctenotus and Lerista probably result from the fact that Lerista have a relatively shorter head than Ctenotus. All Lerista species, surface-dwelling and fossorial, have short heads compared to primitive sphenomorphine lizards. Fossorial species of Lerista have elongate trunks, and consequently their heads are shorter in proportion to trunk length than those of surface-dwelling Lerista. However, most fossorial species of Lerista are longer and heavier than any of their surface-dwelling congeners, and the heads of these fossorial species are large relative to the prey they encounter. As a consequence, the diets of large fossorial species of Lerista do not appear to be limited by their morphological specialization for sand-swimming.

NON-MAMMALIAN thrombocytes are nucleated cells which have been shown to have a haemostatic function paralleling that of mammalian platelets. Thrombocytes are active in the promotion of clots1 and clot retraction2, and respond in vivo to damage of the vessel wall by aggregating to form a plug3. Platelets have been shown to aggregate in the presence of adenosine diphosphate (ADP)4 and therefore it seemed pertinent to study aggregation of thrombocytes with compounds and techniques used in the study of platelets. Although the term thrombocyte is frequently used as a synonym for the mammalian platelet, in this paper it is used solely to describe the nucleated, non-mammalian haemostatic cell.

germinating were similar in the two habitats. Burning reduced the number of native species and seeds that germinated, and to a lesser extent the number of exotic species and seeds that germinated from the seed bank. In the field survey, intact chaparral areas had greater numbers of native species and greater native cover than roads, whereas road areas had greater numbers and cover of exotic species. Several species were found only in field surveys; in particular, few chaparral shrub seeds germinated from the seed bank. Similarity between the seed bank and vegetation was low in both chaparral and road sites. The results suggest that although many native species of chaparral plants are present in the seed bank, planting of some species may help accelerate recovery in disturbed areas.

1. 1. Standard metabolic rates, measured for the lizard Anniella pulchra at 6 and 13°C, were statistically identical, showing notable thermal-independence at low temperature. 2. 2. Metabolic rates, measured at 25 and 30°C, were significantly less than the rates predicted by standard equations. 3. 3. Thermal-independence and reduced aerobic metabolism at temperatures above the preferred range may result in water and energy savings in the fossorial habitat. 4. 4. Body-mass adjusted comparisons with other lizards suggest that reduced metabolism may be a correlative adaptation in small, fossorial lizards.

MANY reptiles drink (Minnich, 1979, 1982). The California legless lizard, Anniella pulchra and the amphisbaenian, Rhineura floridana, gained mass when placed in moist sand (Bogert and Cowles, 1947). Krakauer et al. (1968) demonstrated that Amphisbaena alba, A. caeca, R. floridana, Cylindrophis rufus and Typhlops platycephalus did not gain mass in moist soil unless their mouths were in direct contact