540 



NATURE 



[September 29, 1904 



deer, the nilgai, gnu, eland, buffaloes and European bison, 

 giraffes, and a fine series of Prjevalsky's horse were greatly 

 admired. Mr. R. Lydekker (the leader of the party) and 

 Prof. Ewart pointed out the interesting features of the rarer 

 forms. The party was afterwards entertained to lunch, and 

 conducted through the picture galleries of the abbey. 



On Monday morning, August 22, Dr. C. W. Andrews 

 gave an address on Egyptian Eocene vertebrates and their 

 relationships, particularly with regard to the geographical 

 distribution of allied forms. 



Prof. Keibel, of Freiburg, exhibited some " Normen- 

 tafeln " of the development of V'ertebrata, and also some 

 original drawings of embryos of apes. He stated that 

 although there is a close resemblance between these and 

 human embryos in a similar stage (as Selenka has shown), 

 there are found on further examination various differences 

 — apart from the tail — not only between human and Simian 

 embryos, but also between those of different species of apes, 

 so that the species may be determined without difficulty 

 in embryos from the fourth to the fifth weeks. 



Then followed communications by Mr. A. E. Shipley, 

 F.R.S. (on behalf of Dr. Elliot Smith), on Looss's researches 

 on Ankylostoma duodc7ialc (miner's worm) ; by Prof. G. N. 

 Calkins on Cytoryctes variolae, Guarnieri, the organism of 

 small-pox ; and by Dr. J. A. Murray on the biological signifi- 

 cance of certain aspects of the general pathology of cancer 

 (for abstracts see N.^ture, September 22, p. 519). 



Dr. T. H. Bryce demonstrated a series of slides illus- 

 trating the histogenesis of the blood of the larva of Lepido- 

 siren. 



Mr. J. W. Jenkinson gave an account of the origin of 

 the cleavage centrosomes in the egg of Axolotl. The middle 

 piece of the spermatozoon, after forming the centre of the 

 sperm-sphere and sperm-aster, completely disappears. At 

 a later stage a centrosome is formed from the sperm-nucleus, 

 and this divides to give rise to the cleavage centrosomes. 

 A watery substance collects in vacuoles in the centre of the 

 sperm-sphere, which suggests that the sperm introduces 

 into the ovum a hygroscopic substance. 



Four papers from the Irish Fisheries Laboratory were then 

 read by Mr. Tattersall. 



Messrs. E. W. L. Holt and W. M. Tattersall described 

 some new and rare Schizopoda from the Atlantic slope on 

 the west of Ireland, Mr. Tattersall some Isopoda, and Mr. 

 G. P. Farran some Copepoda from the same region. Many 

 of the Isopoda and Copepoda collected appear to be identical 

 with, or closely allied to, Norwegian forms. Mr. Tattersall 

 also gave a brief account of a new species of Dolichoglossus. 

 It was found in Ballmakill Harbour, co. Galway, in coarse 

 sand and mud at extreme low water spring tides, eight to 

 twelve inches below the surface, in tubes of sand cemented 

 by mucus. A nearly complete specimen measured 12-5 cm. 

 Its chief points of interest are two proboscis pores, complete 

 and continuous lumen of stomochord, and the great size of 

 the pericardium. 



The proceedings on Tuesday morning, August 23, were 

 opened by Prof. Graham Kerr's account of the work of the 

 late Mr. J. S. Budget t on the development of Polypterus. 

 A series of lantern slides, most of which had been prepared 

 from Mr. Budgett's drawings, showed that as regards 

 external characters the development was very like that of 

 an amphibian. There is a pair of true external gills and 

 a pair of cement organs. Dr. Harmer and Prof. Bashford 

 Dean spoke in appreciative terms of Mr. Budgett's work. 



Mr. E. J. Bles contributed some notes on the develop- 

 ment of Pliyllo medusa hypochondrialis, Cope. The material 

 described was obtained by Mr. Budgett in South America. 

 Just before hatching paired cement organs are present iis 

 vestigial structures, but soon disappear without having 

 become functional. This indicates that Phyllomedusa is 

 probably descended from a form which, like our European 

 Hyla, was hatched as a heavily yolked larva which hung 

 from its cement organ until the yolk was absorbed. The 

 amount of yolk in the egg of Phyllomedusa (which is now 

 large) has probably only comparatively recently increased. 

 There is also a glandular frontal organ in Phyllomedusa 

 probably of use in assisting the embryo to escape from the 

 egg-membranes. The thyroid gland in Phyllomedusa differs 

 from that of other tadpoles, and is more like the early 

 thyroid of Ammoccetes, as it reaches along the whole length 

 of the floor of the buccal cavitv. The subnotochordal rod 



NO. 1822, VOL. 70] 



is also conspicuous. The pectoral lymph-hearts in this, as 

 in other tadpoles, appear not at the metamorphosis, but 

 when the tadpole has still a solid intestine and the yolk has 

 almost disappeared from all the other tissues. The wall 

 of the lymph-heart appears to be derived from an outgrowth 

 of the posterior cardinal vein, and before the valves are 

 formed the lumen of the lymph-heart contains blood 

 corpuscles. 



Prof. C. S. Minot then communicated three papers. In 

 the first he presented the theory of cellular rejuvenation, 

 which he claimed must be defined as the increase of the 

 nuclear substance in proportion to the amount of the proto- 

 plasm. This increase occurs during the period of segment- 

 ation of the ovum, is the immediate result of impregnation, 

 and results in the production of rejuvenated cells, i.e. cells 

 with a very small amount of protoplasm around their nuclei. 

 These cells and their descendants then enter upon a career 

 of cellular senescence. In an experiment with telegony 

 Prof. Minot used females of a known race the virgin does 

 of which were allowed to breed with a male of entirely 

 different strain, about half the offspring having the paternal 

 colour. The same does were afterwards allowed to breed 

 with bucks of their own race, and in no case was there any 

 trace of the colour of the telegonous father in the offspring. 

 Prof. Minot gave an account of the Harvard embryological 

 collection, which comprises more than 800 series of sections 

 of vertebrate embryos, and pointed out its value in aiding 

 research. 



Dr. G. H. F. Nuttall, F.R.S., gave a paper on the pre- 

 cipitin tests in the study of animal relationships. He briefly 

 described the methods of testing by means of precipitating 

 antisera, and pointed out two practical applications of the 

 test — in legal medicine for the identification of blood stains, 

 and in the study of animal relationships. For example, 

 this method has demonstrated a close relationship between 

 Hominidae and Simiidae, a more distant one between these 

 and Cercopithecidae, a slight bond connecting all of these 

 w-ith the New World monkeys. The lemurs do not appear 

 to be connected with the Primates anv more than do other 

 mammals. The test appears to connect the Cetacea with 

 the Ungulata, and the Reptilia with the Aves. 



In reply to a question by Prof. Poulton, Dr. Nuttall stated 

 that tests of the blood of Echidna do not indicate any re- 

 lationship between this animal and other mammals. 



Prof. E. B. Poulton, F.R.S., gave a paper on the mimetic 

 resemblance of Diptera to Hymenoptera, to which Lord 

 Avebury, Mr. Bateson, and Mr. O. Latter added further 

 observations. 



In the afternoon of August 23 three addresses dealing 

 with the evolution of the horse were delivered by Profs. 

 Osborn, Ewart, and Ridgeway (for abstracts see Nature, 

 September 22, p. 520). 



On Wednesday morning, August 24, Mr. J. W. Jenkinson 

 gave an account of the effects produced by growing frog- 

 embryos in salt and other solutions. The object of the 

 experiments was to discover whether the distortion of 

 development produced by growing the eggs of the frog in 

 a o 625 per cent, solution of sodium chloride is due to the 

 physical (increased osmotic pressure) or chemical properties 

 of the solution or both. The monstrosity consists of (il 

 failure of the blastopore to close, so that a large persistent 

 yolk-plug is produced, and (2) the failure, total or partial, 

 of the medullary folds to close. Solutions of chlorides or 

 bromides of barium, calcium, &c., cause death of the egg 

 at an early stage, possibly due to the formation of 

 insoluble carbonates in the cells. When kept in chlorides 

 or bromides of potassium, lithium, &c., the egg loses its 

 power of elongating in the direction of the long axis of the 

 embryo, but differentiation of the germ-layers and organs 

 proceeds ; ultimately degeneration and disintegration of the 

 tissues set in. In sodium or magnesium chlorides or nitrates 

 the embryo is able to elongate, but development is abnormal. 

 In solutions of urea or sodium sulphate development is 

 nearly or quite normal, especially in the latter solution, in 

 which the tadpoles will live for weeks. Mr. Jenkinson 

 thinks the various phenomena are to be attributed to the 

 poisonous properties of the substances employed. 



Prof. M. M. Hartog showed lantern slides of magnetic 

 models of cellular fields of force. He remarked that there 

 is in the dividing cell a dumb-bell-shaped structure recalling 

 the figure of the " field of force " manifested by sprinkling 



