376 RETORT— 1879. 



in the anterior part, one becomes the egg-cell, attached to two others, which have 

 elongated as the ' Gehiilfinnen ' or ' Synergidfe ' of Strasburgher, and become 

 packed into the top of the sac ; the fourth remains suspended in the protoplasm of 

 the sac, and is said by Strasburgher to fuse with one of the similarly produced 

 masses below, the product becoming the nucleus of the embryo sac. The three 

 remaining nuclei are the ' antipodal cells ' of authors. The writer confirms these 

 views, except that the actual blending of the two nuclei has not been seen : in 

 Ranunculus, Anthericurn, and other plants, however, the evidence is sufficient to 

 render this view most likely, since two nuclei in all stages of approach occur, as 

 well as sacs with one large central nucleus. 



The fertilised ovum divides by a horizontal wall into two similar cells ; the 

 upper one becomes the suspensor, and divided by cross- walls only ; the lower is cut 

 by walls in alternating planes at right angles to one another into a few-celled simple 

 embryo, showing no differentiations into tissues, or into cotyledons, stem, root, &c. 

 Short reference was made to the proposed homologies for these structures in the 

 embryo sac, and especially to the reasons against accepting the older views as to 

 the correspondence between the synergidae and the canal-cells of the archegonium. 



Confirmatory results have also been obtained in Butomus, Ranunculus, Alisma, 

 Anthericurn, and others. The views of Vesque do not appear to be supported by 

 these researches ; and those of Warming appear to involve considerable difficulties 

 as to the meaning of the embryo sac nucleus. 



3. On the Homologies of the Cephalopoda. By J. F. Blake. 



The flexure of the intestine in Cephalopoda and Pteropoda is ' pedal,' and that 

 of other Odontophora, ' cephalic ; ' and the body of a cephalopod must be placed 

 with the mantle cavity horizontal for comparison with a gastropod. The arms are 

 not homologous with the foot, but form an ' antivelum.' The labial and tentacular 

 processes, and not the individual tentacles of a Nautilus are shown to be homo- 

 logous to the arms of an Octopod. The hood is associated with the aptychus of the 

 Ammonite, the shell of an Argonaut, and the neckplates of a Sepia. The Ascoceras 

 is cited to show the relations of the Sepia-bone to the Nautilus shell. 



4. On Cyclops. By Marcus M. Hartog, M.A., B.Sc. 



The nervous-cord of Cyclops is essentially Copepodan in type, it is not distinctly 

 ddated into special ganglia containing cells evenly distributed up to the third thoracic 

 segment, which is here continued by a fibrous commissure to a ganglion in the next 

 segment. Beyond this are no cellular elements in the cord, which bifurcates in the 

 second abdominal segment, and the branches terminate in the furca. The sensory 

 and motor nerves appear to be wholly distinct, the latter coming off at a higher or 

 deeper level. All the sensory nerve-fibres pass through a bipolar ganglion cell near 

 their distal termination. Minute rounded spaces in the hypoderm, especially one at 

 the base of the last thoracic limb, and a pair on either side of the upper face of the 

 front of the head, appear to be auditory organs (containing one or more minute, 

 irregular, highly-refractive corpuscles in the male). Respiration in Cyclops is 

 entirely anal. 



5. On Mimusopeai) a Section of the Order Sapotacece. 



By Marcus M. Hartog, M.A., B.Sc. 



In this paper the genus Dipholis is merged in Bumelia, and the genera Iinbri- 

 caria, Labrainia, and Muriea in Mimusops : a review of the differential characters 

 hitherto relied on showing their inadequacy from every point of view — even con- 

 venience. 



6. On Solid-mounted Preparations. By L. C. Miall. 



