It was not until many centuries had passed that the parts began to be regarded from the point of view of their essential nature and of their mutual relations; that is, morphologically instead of organographically.
The tisallus (thallome) is a plant-body which is not differentiated into the members root, stem and leaf; it is the morphologically simplest body, such as is of common occurrence in the lower plants (e~.
This pad varies much; it is morphologically the homologue of the pair of basiventral elements which by their lateral extension give origin to the corresponding ribs.
The former is morphologically the more primitive condition, and is found in the overwhelming majority of birds, including many Passeriformes.
Morphologically, the spiders are remarkable for the concentration and specialization of their structure, which is accompanied with high physiological efficiency.