Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

3, pt. 3

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

3, pt. 2

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

2, pt. 2

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

2, pt. 3

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

1, pt. 1

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

2, pt. 1

The evolution of man: a popular exposition of the principal points of human ontogeny and phylogeny. From the German of Ernst Haeckel.

1

Handbuch der vergleichenden und experimentellen entwicklungslehre der wirbeltiere, bearb. von prof. dr. Barfurth [u.a.] hrsg. von Oskar Hertwig.

1, pt. 2

The evolution of man; a popular exposition of the principal points of human ontogeny and phylogeny.

"Remarks and references to literature": vol. 2, p. [459]-490.

The evolution of man : a popular exposition of the principal points of human ontogeny & phylogeny /

Bound in green publisher's cloth with gilt-stamped spine, blind-stamped boards, and yellow coated endpapers.

Software educativo para el aprendizaje creativo del curso “Embriología comparada”

Recibido 4 de abril de 2011 • Aceptado 26 de agosto de 2011 • Corregido 13 de octubre de 2011      El estudio del que da cuenta este artículo tuvo como objetivo diagnosticar la necesidad de un software educativo sobre el proceso de segmentación en animales para promover el aprendizaje creativo de los estudiantes en el curso Embriología comparada, de la Universidad Pedagógica Experimental Libertador en Barquisimeto, Estado Lara, Venezuela. Se apoyó en una investigación de campo de naturaleza descriptiva, los sujetos en estudio fueron 32 estudiantes cursantes de la asignatura durante el lapso académico I-2009. Se diseñó y aplicó un cuestionario en formato tipo Likert, el cual fue validado a través del juicio de expertos y su confiabilidad determinada con el Coeficiente Alfa de Cronbach. Los datos fueron recolectados y posteriormente analizados mediante la estadística descriptiva, se construyeron tablas de frecuencias y porcentajes para la presentación de los mismos. Los resultados revelan que existe, entre los estudiantes de Embriología comparada, una muy alta necesidad de contar con un software educativo que permita su aprendizaje creativo, un recurso en formato electrónico adaptado a las nuevas tecnologías de la información y la comunicación.

A text-book of vertebrate embryology, treated from the comparative standpoint.

"Literature" at end of each chapter.

Class Work in Vertebrate Comparative Anatomy -- Embryology

On verso: Prof. J. E. Reighard standing by the middle window. Herbert S. Jennings at the left of the right hand window.

Floral development and embryology in the early-divergent grass Pharus

A detailed study of floral ontogeny, anatomy, and embryology in two (of six) species of Pharus is presented as part of a series of comparative investigations on early-divergent grasses. Pharus is a taxonomically isolated genus belonging to the earliest-diverging grass lineage with a true grass spikelet. It is unusual in possessing remarkably dimorphic florets: male florets possess two lodicules, six stamens, and a pistillode, whereas female florets lack lodicules entirely but possess six staminodes and a tricarpellary ovary with three stigmas. The rudimentary lodicules in male florets are initiated after the stamen whorls. There are most commonly six androecial organs, but in some florets, a five-staminate condition was observed, resulting from suppression of the abaxial stamen from the inner whorl, or even a four-staminate condition resulting from subsequent fusion of the two adaxial outer stamens (i.e., elements of both whorls). Thus, the pattern of floral zygomorphy in Pharus differs from that of many other grasses. Centrifixed anther attachment is reported for the first time in Pharus, resembling the condition in another early-divergent grass, Anomochloa, though anthers are introrse in Anomochloa compared with latrorse in Pharus. Anther wall development is of the reduced type in Pharus, in contrast to most other monocots. Microsporogenesis is of the successive type, as in many other monocots. The ovary develops from three distinct primordia and is unilocular with a single ovule and a pronounced ovary beak that is highly characteristic of Pharus. There is a hollow style, in contrast to the solid styles that are common in many other grasses. The embryo is highly differentiated, as in other grasses, with a distinct epiblast and a small cleft between the scutellum and the coleorhiza.

Comparative Cytogenetics Of Physalaemus albifrons And Physalaemus Cuvieri Species Groups (anura, leptodactylidae).

Recently, Physalaemus albifrons (Spix, 1824) was relocated from the Physalaemus cuvieri group to the same group as Physalaemus biligonigerus (Cope, 1861), Physalaemus marmoratus (Reinhardt & Lütken, 1862) and Physalaemus santafecinus Barrio, 1965. To contribute to the analysis of this proposition, we studied the karyotypes of Physalaemus albifrons, Physalaemus santafecinus and three species of the Physalaemus cuvieri group. The karyotype of Physalaemus santafecinus was found to be very similar to those of Physalaemus biligonigerus and Physalaemus marmoratus, which were previously described. A remarkable characteristic that these three species share is a conspicuous C-band that extends from the pericentromeric region almost to the telomere in the short arm of chromosome 3. This characteristic is not present in the Physalaemus albifrons karyotype and could be a synapomorphy of Physalaemus biligonigerus, Physalaemus marmoratus and Physalaemus santafecinus. The karyotype of Physalaemus santafecinus is also similar to those of Physalaemus marmoratus and Physalaemus biligonigerus owing to the presence of several terminal C-bands and the distal localization of the NOR in a small metacentric chromosome. In contrast, the Physalaemus albifrons karyotype has no terminal C-bands and its NOR is located interstitially in the long arm of submetacentric chromosome 8. The NOR-bearing chromosome of Physalaemus albifrons very closely resembles those found in Physalaemus albonotatus (Steindachner, 1864), Physalaemus cuqui Lobo, 1993 and some populations of Physalaemus cuvieri Fitzinger, 1826. Additionally, the Physalaemus albifrons karyotype has an interstitial C-band in chromosome 5 that has been exclusively observed in species of the Physalaemus cuvieri group. Therefore, we were not able to identify any chromosomal feature that supports the reallocation of Physalaemus albifrons.