182 SUMMARY OF CURRENT RESEARCHES RELATING TO 



but differs in the reduction of the mouth-parts, here adapted only for 

 piercing and sucking. The mandibles, maxillae, and paraglossae are 

 mere styles, the mandible being furnished with two teeth at the tip. 



Collembola from Franz- Josef Land.* — Mr. G. H. Carpenter reports 

 on the collection of Collembola made by Mr. W. S. Bruce in Franz- Josef 

 Land. Seven species are represented in the collection from this new 

 locality, including one new species — Isotoma brevicauda. The distribu- 

 tion of northern Collembola, as summed up by Carpenter, lends support 

 to our belief in a Pliocene or Pleistocene land-connection to the north 

 of the Atlantic Ocean, a belief already upheld by so much evidence, 

 both geological and zoological. 



j3. Myriopoda. 



Luminosity in Centipedes.f — Rose Haig Thomas records an inter- 

 esting observation on Geophilw. It had discharged its " fluid " on a 

 dozen or so of red ants which were pursuing it, so that a curving throad 

 of light seemed to have a scattered tail of brilliant points. When the 

 centipede was dropped into a tumbler, it " splashed out a mass of light. 

 Hurriedly placing my hand over the tumbler to prevent the insect from 

 escaping, I felt suddenly a strange prickly sensation, such as is caused 

 by a slight contact with electricity, so that I hastily removed my hand, 

 calling to a friend who, placing her hand over the tumbler, felt the same 

 thing. I lit another match and watched the Geophilw writhe the light 

 out of its body in blue-green flashes. It soon ceased to shine, having 

 probably exhausted all the luminosity on its enemies." Defence seems 

 certainly to be one of the uses of this secretion. 



Spermatogenesis of Scolopendra.* — M. W. Blackman has made a 

 series of observations on the spermatocytes and spermatids of an unde- 

 termined species of this genus. He finds that the spermatocytes, at the 

 time of their formation, are small cells with very little cytoplasm. The 

 chromatin, with the exception of that of the accessory chromosome, 

 becomes arranged in a spireme and the cytoplasm increases in amount. 

 Next the spireme breaks down, and forms a reticulum which stains 

 feebly, and becomes finer and finer until it is no stronger than the cyto- 

 plasmic reticulum ; meanwhile the accessory chromosome increases 

 enormously in size. Later the chromatin reappears in the form of 

 diffuse masses, which quickly take on the tetrad shape ; at this stage the 

 accessory chromosome has decreased in size, and become irregular in 

 outline ; it subsequently recovers its spherical shape, and persists till 

 the disappearance of the nuclear plate preparatory to division. Soon 

 after the tetrads are formed, the centrosome appears, divides into two, 

 and the two halves as usual migrate to the poles of the nucleus. After 

 the last maturation division, a portion of the nucleus is budded off, and 

 passing through the cytoplasm, is extruded from the cell ; to this pro- 

 truded portion the author gives the name of itomere. Its formation and 

 protrusion is accompanied by the formation of yolk-masses, and by a 



* Soi. Proc. R. Dublin Soc. ix. (1900) pp. 271-8 (18 tigs.). 



+ Nature, lxv. (1902) p. 223. 



X Kansas University Quarterly, x. (1901) pp. 61-76 (3 pis.). 



