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Notes: Abstract The growth habit of the rosette plant Plantago lanceolata is highly variable, and many vegetative and reproductive traits co-vary. At one end of the range plants have relatively few but long and erect leaves, form few daughter rosettes, and produce a limited number of large spikes, with relatively heavy seeds. Plants at the other end of the range have the opposite characteristics. This suite of characters was shown to correlate with the height of the vegetation in mid-summer. The causes for this association between different traits were investigated in different experiments, with the following results:〈list xml:id="l1" style="custom"〉Plants from two contrasting habitats both react strongly to light intensity and the red to far-red (R/FR) ratio of the ambient light. Light intensity mainly affected plant size, whereas light quality affected the growth habit. Populations differ in their mean response rather than in the level of plasticity (i.e., slope of the reaction norms). Experiments show that genetic factors (population effects), R/FR ratio, and hormone treatments (GA or CCC) have similar effects on morphology, and are largely additive and interchangeable.Ten different populations were grown in a common garden, so that the genetic (clonal) correlation within populations, and their bivariate phenotypic means could be compared. Trait combinations which deviated in the same direction (both higher of both lower than the mean over all populations) on average had positive clonal correlations within populations, whereas combinations which deviated in opposite directions had negative correlations.Artificial selection on leaf length, performed under a high or a low R/FR ratio showed clear responses to selection, with heritabilities around 0.4. Correlated responses were found in many other traits, and genetic correlations were similar to the trait associations for the means of different natural populations. Correlated responses to selection depended on environmental circumstances. Under a high R/FR ratio (sun) evidence for a size/number trade-off was found for leaf length and leaf number. Under a low R/FR ratio, however, a trade-off between leaf length and leaf quality was found.In conclusion, the trait associations that are so characteristic for the growth habit in Plantago lanceolata are probably due to differences in hormone levels or activities. Genes and environmental factors affect growth habit in similar ways, by tapping into this regulatory mechanism. In the field, selection can lead to concerted changes in the mean of different traits, but changes in plasticity will be slow.

Notes: Zusammenfassung In vergleichend photometrisch, chemisch und volumetrisch durchgeführten Liquorgesamteiweißbestimmungen an 62 Liquores mit normalen und krankhaft erhöhten Eiweißgehalten wird folgendes gefunden: 1. Die volumetrisch gefundenen Gesamteiweißwerte liegen bis zu 40% unter den chemisch und spektralphotometrisch nachweisbaren Werten. Die volumetrisch bestimmten Gesamteiweißwerte streuen erheblich mehr als die mit den beiden anderen Methoden gefundenen Werte. 2. Die Gründe für dieses Verhalten werden kurz besprochen und in einer photometrischen Methode eine bessere und im Rahmen der klinischen Liquoreiweißdiagnostik gut anwendbare Methodik gefunden. 3. Die Grundlagen der Methode beruhen auf der Bildung eines Biuret-Proteinfarbkomplexes, dessen Faktoren und seine Beeinflussung durch Alterung, Temperatur, Eiweißkonzentration, sowie Stabilität des Biuret-Reagens untersucht werden. 4. Die photometrische und chemische Methodik zeigen eine innerhalb des statistischen Zufallsbereiches liegende Korrelation und stimmen somit praktisch überein. 5. Die spektralphotometrische Methode kann als einfache und exakte Methode zur Bestimmung der Liquorproteine für die klinische Liquordiagnostik empfohlen werden. Aus angeführten Gründen liegt die obere „Norm“-Grenze der Methode mit 45 mg-% etwas höher als die der kjeldahlometrischen und volumetrischen.