ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 155 



Vesicular Secretion.* — A. N. Mislawsky has studied the process of 

 secretion in the superficial mandibular gland of the rabbit, which is not 

 a salivary gland, but nearer the axillary gland in man and the inter- 

 digital gland in ruminants. It illustrates the so-called " vesicular " 

 secretion. The secreted material accumulates at the distal portion of 

 the cell, which bulges out like a dome and is extruded into the lumen 

 of the gland. Mislawsky shows that there is an intense nuclear multi- 

 plication on the part of the glandular cells. 



Junction of Papillary Muscle and Chordae Tendinese.f — Mont- 

 gomery P. Paton has studied this mode of attachment in view of the 

 fact that there is no true sarcolemma over the cells of the cardiac 

 syncytium. The apex of the musculus papillaris is ensheathed by a 

 covering of dense fibrous tissue, continuous with the endocardium. 

 The chorda? arise from the free surface of this investment or helmet, 

 while from its deep aspect numerous well-developed trabecular descend 

 and freely ramify amongst the cardiac muscle-cells. It is here that the 

 junction of the cardiac syncytium and the chorda? tendinese occurs. 

 The more central of the fibres or trabecular insinuate themselves in the 

 most intimate fashion between the muscular elements, so that there 

 results an interdigitating svstem of fibrous tissue and cardiac muscle. 

 The interstitial cement material is therefore responsible for the strength 

 of the junction. 



Mast-cells and Plasma-cells. $ — L. H. Huie discusses these ele- 

 ments. She records the mitosis of the former in the skin of foetal 

 mice. She does not find any plasma-cells in Malpighian corpuscles or 

 in germ centres. They are abundant in the splenic pulp and in the 

 siuuses of lymphatic glands. Their lymphocyte nature must be ex- 

 cluded. They seem to arise from the endothelial cells lining the blood- 

 vessels. 



Changes in Nuclei in Varying • Physiological Conditions. § — E. 

 Wace Carlier gives a brief account of some of the changes exhibited by 

 nuclei during and subsequent to functional activity and points out the 

 danger of interpreting normal phases as pathological. 



c. General. 



Reaction of Marine Organisms to Light and Phosphorescence. jj 

 Benjamin Moore has experimented chiefly with nauplii of Balanus. The 

 characters of the response are not constant, but vary for the same organ- 

 ism according to the intensity of the light and the previous history of 

 the organism in regard to light. As a general rule, the organism is 

 positive to feeble light and negative to stronger light, and for a con- 

 stant intensity of light at a given moment, previous darkness, or weak 

 stimulation, tends to turn organisms positive, and previous exposure to 

 bright light turns them negative. 



Both the positive and negative behaviour to light may be explained 



* Arch. Mikr. Anat., lxxiii. (1909) pp. 681-98 (1 pi.). 

 t Proc. Scot. Micr. Soc, v. (1909) pp. 22-3. 



\ Tom. cit., pp. 37-41 (1 pi.). § Tom. cit., pp. 82-6 (1 pi.). 



|| Trans. Liverpool Biol. Soc, xxiii. (1909) pp. 1-34. 



M 2 



