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La distribuzione geografica delle 21 specie di Zygaena e 8 specie di Adscitinae viventi nelle Alpi Liguri è stata analizzata sia nei suoi rapporti col resto della fauna paleartica, sia a livello italiano e ligure. Tale indagine ha consentito di evidenziare l'esistenza di numerosi centri di rifugio e speciazione e di mettere in luce diverse aree di transizione primaria e secondaria intese secondo il senso di Thorpe (1983). Il significato adattativo del cosiddetto melanismo littorale (Burgeff 1950) è discusso in termini di conquista di una nuova nicchia ecologica e di caduta nel valore aposematico.
Gli Autori segnalano per il territorio delle Alpi Liguri 144 specie di Molluschi terrestri e 25 specie di Molluschi acquidulcicoli. L'elenco sistematico riporta, per ciascuna specie, eventuali sinonimie, segnalazioni di letteratura e di collezione e i risultati di ricerche di campagna effettuate dagli Autori negli anni 1977-84; inoltre, vengono fornite la geonemia e brevi considerazioni sulla distribuzionc geografica, le caratteristiche ecologichc ed eventuali problemi tassonomici. Segue un esame critico dei taxa di pteseilza dubbia o di incerta collocazione sistematica, ed un breve elenco delle specie presenti nelle aree circostanti l'area in esame, ma assenti in Alpi Liguri. La malacofauna terrestre delle Alpi Liguri (considerate in toto o nei tre Settori del Cuneese, Imperiese e Savonese) viene confrontata con quella di tre settori piu interni delle Alpi Occidentali (Alpi Marittime settentrionali, Alpi Cozie, Alpi Graie), di un settorc alpino meridionale (Alpi Marittime francesi) e di due settori appenninici (Appennino Ligure ed Aipi Apuane), mediante indici di similarit i di tipo binario (presenza-assenza di specie). Vengono inoltre confrontati tra loro gli spettri corologici delle aree sopracitate. L'area studiata non appare uniforme da1 punto di vista faunistico, ma diversamente caratterizzata nei diversi settori. Per la particolare posizione geografica e le peculiari caratteristiche paleoclimatiche, geomorfologiche ed ambientali, il popolamento malacologico delle Alpi Liguri si presenta qualitativamente vario ed ariicchito da correnti rnigratorie di diversa provenienza (alpina, W-mediterranes, appenninicii). Nella caratterizzazione della fauna e degli endemismi, sembra importante il ruolo di area di rifugio assunto dalle Alpi Liguri in epoca glaciale.
Comparing the modern level in the biology of gastrointestinal stem cells with that achieved in the hemopoietic stem cell studies, we can say, using Till's expression (1982), that at present the "morphological phase" in the investigations of the former is continuing. Still urgent is the problem of morphological verification of presumable stem cells in colonic crypts and gastric glands. Also important is to clarify the ways of renewal of the well-differentiated but low proliferating activity endocrine cells, the chief cells of the fundic glands, and the cells of Brunner's glands. Further studies of interaction between epithelial and stromal cells are needed. The knowledge of relationships between stem cells and their differentiated "neighbors" in the niches, as well as of peculiarities of contacts between epithelial cells proper and of the cells with the basement membrane is of major importance. It is also necessary to clarify the mechanisms of the stem cells "anchoring" as well as of the disturbances of this important property during carcinogenesis. Briefly summarized below are the most essential, in our opinion, directions of the study of stem cells; some of these have already been started, whereas others can only be predicted. 1. The isolation from normal tissues of the fractions of intact cells enriched with the stem cells, with their subsequent culture. 2. The clarification of the factors governing the regulation of renewal of stem cells: specific stimulators and inhibitors of proliferation; and characterization of the receptor apparatus of stem cells, particularly for the enteropancreatic hormones. 3. The antigenic characteristic of stem cells. 4. The study of molecular peculiarities of DNA replication of clonogenic cells. 5. The molecular aspects of commitment and differentiation of stem cells. 6. The quantitative and qualitative characteristics of stem cells in the process of carcinogenesis. 7. The qualitative evaluation of the dynamics of formation and disappearance of carcinogenic DNA adducts in stem cells. 8. The clarification of interspecies features of stem cells as well as of their morphogenetic potentialities in onto- and phylogenesis. 9. The characterization of metaplastic changes in stem cells.
The regular or obligate aphytophagy of certain lycaenid butterflies (Lepidoptera) is discussed within the framework of the most recent general classification of the family. A summary survey of all Lycaenidae known to be aphytophagous is presented, together with a brief account of cannibalism and other opportunistic aphytophagy exhibited by normally phytophagous butterflies. The range of food sources (plants, animals, excretions and regurgitations) exploited by lycaenids is reviewed with emphasis falling on the ecology of myrmecophilous early stages and the significance of their ant-related adaptations. Adult feeding and oviposition behaviour reveal further associations with ants. Specificity oflycaenid/ant relationships and the possible biological effects ofaphytophagy on the Lycaenidae are discussed. Finally, speculations concerning the evolution of aphytophagy by these bulterflies are critically presented.
Die jahreszeitlichen Zugmuster der häufigeren Singvogelarten auf dem Col de Bretolet im Herbst sind von Dorka (1966) dargestellt und eingehend analysiert worden. Basierend auf Beobachtungen und FängIingen legte er charakteristische Unterschiede zwischen Kurz- und Langstreckenziehern dar. Aus der Form der Zugmuster konnten in der Folge Rückschlüsse auf die Art der Steuerung der Zugaktivität gezogen werden (Berthold & Dorka 1969). Seither haben sich die Fangzahlen vom Col de Bretolet mehr als verdoppelt und die Fangzeit wurde gegen den Sommer hin ausgedehnt. Dadurch wird es einerseits möglich, bisherige Aussagen zu verfeinern ; andererseits können wesentlich mehr Arten einbezogen werden, und die bisher kaum untersuchte Phase vor der eigentlichen Zugzeit kann analysiert werden. Ein erstes Ziel dieser Arbeit ist es, die jahreszeitlichen Zugmuster nach Fänglingen für möglichst viele Arten darzustellen und damit - ohne eine eingehendere Besprechung der einzelnen Arten - eine Arbeits- und VergleichsgrundIage zu schaffen. Eine Besonderheit der Beringungsstation auf dem Col de Bretolet liegt in der subalpin-alpinen Brutvogelgemeinschaft der Umgebung. Die Durchzugsverhältnisse der Tieflandarten sind dadurch im Vergleich zu anderen Stationen in Europa, die meist im Tiefland liegen, leichter zu interpretieren. Beim Vergleich mit solchen Stationen ergeben sich bei manchen Arten augenfällige Unterschiede in der Form der Zugmuster. Solche Formunterschiede hat auch Denker (1973) beim Fitis Phylloscopus trochilus zwischen Helgoland und dem Festland gefunden. Deshalb sollen die Zugmusterformen der einzelnen Arten sowie von Bretolet und anderen Stationen miteinander verglichen werden. Dabei stehen nachbrutzeitliche Bewegungen, d. h. das Umherstreifen ohne Bindung an den Brutort zwischen dem Ende der Brutzeit und dem Beginn des Wegzuges, im Vordergrund, wobei die Lage der Fangstationen zum Herkunftsgebiet der auftretenden Arten besondere Bedeutung erhält.
Oribatei (Acari, Cryptostigmata) are found in a variety of terrestrial habitats, and many are associatcd with lichens; the relationship ranges from casual to highly dependent. Eighty-three species associatcd with lichens have been surveyed, and a tentative classification, based on their ecological requirements, is presented: Group A consists of species restricted to lichens as a biotope, though occasionally occurring as accidenials in other habitats, Group B consists of species which while preferring lichens as a habitat and feeding source are also adapted to existence on other piants (though in some cases their immatures may be lichen-rescricted); Group C consists of species which, though frequently found on lichens, are equally common in other biotopes, particularly mosses, and must be regartled as much more generalized in their feeding habits. Certain aspects of oribatid-lichen specificity are discussed. The importance of orihatid-lichen associations from tihe polnt of view of soil fertility and energetics is empliasized.