t 



"V 



20 



UMBILICAL VESSELS. 



Sect. Ill 



SECT. 



III. 



THE UMBILICAL VESSELS OF SEEDS AND BUDS 



I.I. Seeds are ajexual offspring like eggs. Some feeds and eggs contain two kinds 



of nourifh, 



ment. 



Other feeds and Jpawn of fifh contain hut one kind of nourijh 



1 . Air-bag in eggs^ and in fome fruits i not in feeds y nor in Jp 



3. Vejfels improperly called umbilical y thofe properly called umbilical confift of ah 



J or bent Si and a placental arterv and 



Seed emhryon and chick beg 



growth by the aSiion of their ahjorbents, 4. Seminal roots of GreWy and chorion 

 of the chick of Malpighi, are refpiratory organs. 5. In what the chick differs from 

 the feed- emhryon. Nothing is found in feeds fmilar to theyolk of the egg. II. i. Buds 

 and bulbs are a paternal offspring ; exa^lly refemhle their parents, 2. Have um- 



bilical veffelsy in 



the Jap -juice rifes in thejpring. Why the hark 



%fily feparated from the alburnum. 3. Sugar in the Jap- juice exijis in the alhiir 



and in roots. Dry rot of timber owing to ft 



Why lower branch 



f.rjl pullulate. 4. Sap ajcends not by capillary attra^fiony but by the 



of ahforhent 



effel 



Injlances of vegetable 



Jels Jometime s a5i as capillary Jyphonsy and as capillary 



Jels coalejce. Why trees do not bleed in fi. 



. Ahforhent vej- 

 5. Umbilical vef 



6. Umbilical v effel s of buds 



'hoje of feeds. Poffefs air-veffels like thoje of the chick. Buds, like eggs.Jep 



/ 



from the parent 



umbilical veffels improperly called placental 



convey nutriment j hence plants become dwarfs if the cotyledons of the feed are de* 

 Jlroyed. Birch- trees die ifjmeared with oil or pitch. 7. Rejervoir oj nutriment 

 the alburnum of trees, and in the roots of biennial plants. Experiment of boiling 



the alburnum and fermenting the liq 



buds are formed at midjummer, they 



be tranjpl anted by inoculation, but in thejpring mujl be ingrafted, and 



grow by inojculation of veffels, like inflamed parts of 



8. 



getation at midji 



A paujt 



New umbilical veffels aSi in autumn, and the barkjep^ 



afily as injpring. Honey -dew. Sap -juice rjfes in winter occajionally both 



/ 



ever^ 



I 



