ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 455 



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Mites in Man.* — Tieche reports that mites belonging to the family 

 Tyroglyphidas occurred in multitudes in the stools of three patients 

 suffering from prurigo. Though it is not likely that the mites had 

 anything to do with the prurigo, their occurrence as temporary endo- 

 parasites seems certain. 



Mites in Tumours.f — Fr. Dahl describes Tarsommus hominis sp. n. 

 found by Saul in a fibroma and carcinoma of the human ovary — a 

 very interesting discovery. He discusses the important question whether 

 this new mite was simply a parasite in the tumours, or was part of the 

 cause of them. It is well known that some of the species of Tarsommus 

 cause cell-proliferation in plants. 



e. Crustacea. 



Habits of Robber Crabs.J — C. W. Andrews describes the habits of 

 Birgus latro on Christinas Island, and publishes an interesting photo- 

 graph showing them climbing trees. In so doing they cling by the 

 sharp points of the walking legs, hardly using the great claws at all. 

 They feed on fruits of various kinds — e.g. of sago-palm and screw-pines, 

 and on carrion. They steal almost anything portable that has been 

 handled. Though probably nocturnal in most cases, they moved about 

 in the forest on Christmas Island in the brightest daylight. They are 

 easily frightened, and scuttle backwards, propelling themselves with 

 their long anterior legs in a series of ungainly jerks. They thrust their 

 abdomen under logs, or into holes among the roots of trees, but 

 they never carry any protective covering. 



Cenobita and Acquired Characters.§ — E. Bugnion describes the 

 exquisite adaptations of Cenobita rugosa, common on the Ceylon coast, 

 to its life within a Gastropod shell. But the creature was once a free- 

 swimming zoasa. What is the significance of its asymmetrisation, 

 reduction, and detailed adaptation ? According to the author, " the 

 asymmetry of the appendages, so marked in this species, should be 

 regarded as a character acquired in the course of phylogenetic evolution, 

 as the result of adaptation to a special mode of life." 



Bugnion would distinguish various grades of " modifications "—that 

 is to say, structural changes brought about in the individual life-time 

 as the direct result of changes in function or in environment. (1) 

 Those that are useless or harmful are not inherited, like those of cir- 

 cumcision and of curtailing fox-terriers. But these do not seem to 

 us to conform to the definition of modifications. (2) Other changes, 

 developing slowly, and saturating more deeply, have a tendency to be 

 inherited, such as hare-lip, syndactylism, polydactylism, ankylosis, and 

 muscular atrophy. Many of these, we submit, are obviously not modi- 

 fications, but expressions of germinal variations. (3) Lastly, there are 

 modifications acquired in the course of the individual lifetime in 

 response to new conditions, and they tend to be inherited, as in the case 

 of Cenobita. But no evidence is given in support of this conclusion. 



* Centralbl. Bakt. Parasitenk., liv. (1910) pp. 32-G (2 figs.), 

 t Op. cit., liii. (1910) pp. 524-33 (2 figs.). 

 \ Proc. Zool. Soc, 1909, pt. iv. (1910) pp. 887-9 (1 pi.). 

 § C.R. Soc. Biol. Paris, lxviii. (1910) pp. 799-800. 



