GULLIVER ON THE MINUTE ANATOMY OF ANIMALS. 141 



the emission of the pollen from the anther, and before the expansion of 

 the stigma, the origin of the primary utricle cannot be referred to the 

 influence of impregnation, nor can it have been derived from the pollen 

 tube pressing before it a fold of the embryo-sac. 



The primary utricle at its first formation being quite distinct from the 

 embryo-sac, even at its apex (although brought into contact with it at 

 a subsequent period, and ultimately penetrating it), cannot result from 

 a depression or involution of the embryo- sac, as is maintained by M. 

 Brongniart. 



The pollen tubes (which after impregnation may be traced in the con- 

 ducting tissue of the style) never reaching the micropyle, but pollen 

 granules being found in abundance in the channel leading to it, and 

 being doubtless brought into contact with the outer surface of the em- 

 bryo-sac through the exostome ; and the first trace of the embryo ap- 

 pearing at this time in the formation of the spherical body at the inferior 

 extremity of the primary utricle Dr. Giraud is led to conclude that 

 the origin of this simple spherical body results from a peculiar process 

 of nutrition, determined by the material or dynamic influence of the 

 fovilla, conveyed through the medium of the primary utricle or sus- 

 pensor. 



The paper was accompanied by a series of drawings representing the 

 ovulum of TropcBolum in the several stages of development described. 



XXV. CONTRIBUTIONS TO THE MINUTE ANATOMY OF ANIMALS.* 



By George Gulliver, F.R.S., &c. 



As minute anatomy is now become more generally interesting than for- 

 merly, and begins to assume the character of an extensive and compa- 

 ratively accurate science, so as to give a new complexion to some of the 

 most important questions in physiology and pathology, and to enable us 

 to submit many old doctrines to a more exact scrutiny than most of our 

 classical anatomists had the means of employing, it appears to me that 

 considerable advantage might arise if different independent observers 

 would more frequently publish a brief yet clear account of the results 

 of their inquiries. Hence I propose to communicate occasionally to the 

 Philosophical Magazine, a series of short notes on the ultimate structure 

 of various animal tissues and on the elementary forms which occur in 

 the fluids, taking the discriptions in all cases from my own observations, 

 and frequently illustrating them with wood-cuts. It will thus be at- 



* From the Philosophical Magazine, June, 1842. 



