1892.] Recent Literature. 
K 
D9 
a 
RECENT LITERATURE. 
Eimer on the Origin of Striped Muscular Tissue.’—Prof. 
Eimer, of Tübingen, endeavors in this treatise to prove that the trans- 
verse striping of muscular tissue is due to increased energy of muscu- 
lar contraction. He refers to the well-known fact that this character 
is seen in muscles which display the greatest energy, while the 
unstriped condition is characteristic of muscles of feeble and slow con- 
tractility. This is shown to be the case in many animals, some of the 
most striking illustrations being drawn from the Mollusca. Among 
the most important observations are those on the muscles of the 
Anthropoda. The author made the interesting observation that the 
thoracic muscles of the house-fly are, during the winter season of tor- 
pidity, unstriped, while with the advent of active life in spring the 
cross-striping appears, and is most developed in summer, the period of 
greatest activity. The various stages of development of the Zwischen- 
scheiben and Mittlescheiben, which are to be seen not only in the same 
individual but in the same fibrilla, are traced and illustrated. It is 
also maintained that the longitudinal division of primitive simple 
muscular masses into fibrille is due to longitudinal stress; and still 
earlier in evolution that muscular tissue is differentiated from homoge- 
nous protoplasm by the same agency. These theses are sustained with 
much plausibility, and they may be regarded as an integral part of 
Neolamarckian doctrine. Prof. Eimer expresses his results in the 
following language: “The cross-banding is the permanent expression 
of contraction waves of the muscle mass caused by nervous stimulus. 
It appears to be in the fullest sense an acquired and inherited pecu- 
liarity.” 
Beecher’s Studies of the Brachiopoda.’—This paper is the 
‘second of a series in which are published the results of a combined 
study of young and adult, living and fossil brachiopods. The facts 
and conclusions reached are of great interest, and are highly important 
to a clear understanding of the group. 
1Die Entstehung und Ausbildung des Muskelgewebes insbesondere der Querstreif- 
ung derselbens als Wirkung der Thatigkeit betrachtet; von G. H. Th. Eimer. Sep- 
arat Abdruck aus Zeitschr. f. wissensch. Zoologie, liii, Suppl. Leipzig, 1892. 
. ` 2Development of the Brachiopoda, Part II. Classification of the Stages of Growth 
and Decline, by Charles E. Beecher (with Plate 1). Am. Jour. Sci., Vol. xliv, Aug., 
1892. 
