PROGRESS OF MICROSCOPICAL SCIENCE. 79 



January, 1873, by Professor A. E. Verrill. The paper records the 

 results obtained by the dredging parties who sailed in the ' Mosswood ' 

 and ' Bache ' steamers, but it is impossible to abstract it. 



The Bed Blood Cells in Mammals, Birds, and Fish. — In the new 

 medical journal, the ' Medical Eecord ' (January 8th), which we hope 

 will prove a successful undertaking, Dr. Ferrier gives an abstract of 

 M. Malassez' paper on the above subject in the ' Comptes Eendus.' 

 It is stated that according to the method recommended by M. Potam , 

 a drop of blood is mixed in exact proportion with some preservative 

 liquid, and introduced into an artificial capillary, which consists of a 

 flattened glass tube, in which the volume is calculated for each unit of 

 length. By means of a microscope, the eye-piece of which is divided 

 into squares, the number of corpuscles comprised within a certain 

 number of squares can be counted. Knowing the length of tube 

 corresponding to the squares and the corresponding volume, one can 

 easily calculate the number of corpuscles in the cubic millimetre. 

 Among the mammals the number varies from 3,500,000 to 18,000,000 

 in the cubic millimetre. The average number in man is 4,000,000. 

 Camels possess from 10,000,000 to 10,400,000. In the goat the 

 number amounts to 18,000,000. The porpoise has 3,600,000— a 

 number exceeding that found in fishes. Birds have fewer than mam- 

 mals. The maximum is 4,000,000, the minimum 1,600,000, the mean 

 being about 3,000,000. Fishes have still fewer, and there is a differ- 

 ence between osseous and cartilaginous fishes. Osseous fishes possess 

 700,000 to 2,000,000. Cartilaginous fishes have 140,000 to 230,000. 

 Thus the number of corpuscles diminishes as one descends the animal 

 series. But the richness of the blood depends not on the mere 

 number, but also on the surface, volume, and weight of the globule 

 in the cubic millimetre, and also on the amount of haemoglobin in each 

 corpuscle. The author has not been able to resolve these questions, 

 but compares the number of the corpuscles with their dimensions. 

 The corpuscles increase in size as we descend the animal scale, so that 

 there is" an inverse proportion between the size and number of the 

 corpuscles. This proportion is not, however, altogether constant, for 

 man has fewer than the dromedary or llama, and at the same time 

 smaller corpuscles. The consequence of this inverse proportion is, 

 that the diminution in the number is compensated by the increase in 

 volume. This is not always exact, however, as birds gain more by the 

 augmentation in volume than they lose by the diminution in number, 

 the weight of the bird's being greater than that of the mammalian 

 corpuscle. 



The Babbit's Ovum, its Fecundation and Development. — In the same 

 journal, the ' Medical Eecord ' (January 8th), Dr. E. Klein has an 

 admirable paper on the above subject. He gives a valuable abstract of 

 Dr. Carl Weil's researches on the subject. He states that since the 

 discovery of spermatozoa in the ovum of the rabbit by Barry,* 

 it has been held by all embryologists that the spermatozoa form 

 the most important part of the sperma as regards the fecundation. 



* ' Philosoph. Trans.,' 1838-40. 



